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User Guide for SDR v2.5 - Unesco Virtual Laboratory Toolkit

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1. Step 6 Select security parameters for this session You need to specify the security of session Authentication PGP group3 x group2 group1 Goli Montasser Kohsari gmon E Enter passphrase for Goli Montasser_Kohs Passphrase k Encryption X503 CN Peter Kirstein OU Compu CN Edmund Whelan OU Comput d CN Goli Montasser Kohsari lt lt Back Next gt gt Accept Cancel Figure 7g e Authentication you can choose the type of authentication by clicking on the authentication button and choosing one of the following options none PGP X509 PGP CERT X509 CERT Note To use X509 you should set X509STATE see Appendix 2 None The session is a plain session not authenticated PGP PGP CERT List the secret keys available for authentication Click on the key which you want to use for the digital signature and provide the password in the lower window If you choose PGP CERT then the Certificate is also sent If you have encrypted your secretkey ring using the smart card then secring pgp exists in your SDR home directory Then choosing the PGP option will open a window requesting the Smart Card location and password For more detail on Smart Card see Appendix 1 Section 1 2 3 18 SDR v 2 5 User Guide X509 X509 CERT A window will be opened requesting the PSE location and the PSE password Set up your PSE or MPSE see Appendix 1 Section 1 2 2
2. 3 3 Seeing what sessions are on Main Window The list of sessions in the Main SDR Window is by default a list of all sessions in alphabetical order By clicking on a session a Session Information Window for that session opens up displaying details of when the session will take place It is possible to customise the list in the Main Window to only show preferred sessions each session can be marked as preferred or not current sessions or future sessions To do that click the Preferences button in the Main Window and select the appropriate option in the Preferences Window Sessions This window also presents you with the option of hiding test sessions SDR v 2 5 User Guide If you select Preferred Sessions you can choose which sessions to be listed by deselecting the sessions you do not want listed in the list of sessions in the right hand side of the Preferences Window Sessions Sessions marked visible will be displayed in the Main Window You can also select sessions that you do not want listed by clicking on them with the right mouse button in the Main Window The Interface tab in the Preferences Window allows you to choose to have the sessions listed by type broadcast meeting test rather than alphabetically And you can choose not to have the type displayed at all Greyed out session announcements are sessions which are not currently running Daily Listings Window July August Sun Mon Tue Wed Thu Fri Sat Sun Mon
3. e commands for signing validating coding and decoding of files e commands for the operation of certification authorities and the interaction between certification authorities and certified users e all external data codlings according to ASN 1 BER and DER e all functions take the millennium into account e safe storage of all security relevant information of the user in a so called personal security environment PSE e optionally support for B1 chipcard readers and Smart Cards Deutsche Telekom Schlumberger and GemPlus is available thus upgrading to e Secude Security Grade High e optionally available is secure access to the public X 500 Directory for storage and production of certificates and revocation lists via LDAP 1 2 2 2 Secude PSE and Smart Card Technology With the Secude security infrastructure every participant is in possession of a private and a public key The public key is certified by a certification authority CA and digitally signed This procedure is comparable to the issuing of an ID card Secude keeps each user s keys in a Personal Security Environment PSE The PSE is protected with a password or PIN Personal Identification Number which only the owner of the PSE should know The PSE is available in two versions as software PSE or as a Smart Card The use of Smart cards simplifies security operations and is mandatory in some secure applications For this reason we have ensured that the secure conferencing d
4. 1 2 2 Secude There are many security toolkits Our implementation of SDRv2 5 uses Secude so we give a brief overview of its facilities The Secude development kit is a library that offers well known and established symmetric and asymmetric cryptography for popular hardware and operating system platforms The development kit consists of a set of functions which allows the incorporation of security in practically any application e g client server e mail office applications and documentation in Hypertext Markup Language HTML which describes in detail the C programming interface There are also various commands collected in a security command shell to ensure an immediate deployment of security 1 2 2 1 Secude development kit provides e asymmetric cryptographic functions such as RSA DSA e symmetric cryptographic functions such as DES Triple DES IDEA RC2 RC4 e hash functions such as SHA SHA 1 MD5 RIPEMD 160 e Diffie Hellman key agreement e security functions for proof of origin data integrity non repudiation and confidentiality on the basis of digital signatures and also symmetric and asymmetric encryption e X 509 certification functions handling of certification paths and handling of revocation lists e Public Key Cryptography Standards PKCS e defined interfaces such as Authentication Framework AF Generic Security Services API GSS API e Privacy Enhanced Mail PEM MailTrusT 48 SDR v 2 5 User Guide
5. 3 6 Creating a Session Announcement eene 13 3 7 Making a Quick Call nets 21 3 8 SDR Preferences Window Lease ssec ecce ccce eene 24 3 8 1 SDR Preferences Window SesSionSs 122111111111111111112 24 3 8 2 SDR Preferences Window Interface 2222222111111111122 25 3 8 8 SDR Preferences Window Tools ccccccccccccccceeeeeeeeeeeeeeeees 26 3 8 4 SDR Preferences Window WebD cccccccccccccceceeeeeeeeeeeeeeeees 27 3 8 5 SDR Preferences Window YOU ccccccccccceeccccceeeeeeeeeeeeeeees 27 3 8 6 SDR Preferences Window Security sssessuuussse 28 3 8 6 1 Generating DES Key eeeeeeeeeeeeea aaa aaa eeaanaaaaaace 29 3 8 6 2 Receiving Encrypted Authenticated sessions 31 3 8 6 3 Viewing an authenticated and encrypted session 32 3 8 6 4 Generating and Receiving keys sssseesssssss 33 3 8 6 5 Generating GrOUD Keys cer ORE RR eH ie 33 3 8 6 6 Receiving and storing Key information 38 3 9 b Ending SDR EE eee ikea 39 4 o NIIT 40 SDR v 2 5 User Guide Appendix Appendix 1 Security Technology e eeeeeeeeee eene enne Appendix 2 Configuration and Software to use With SDR SDR v 2 5 User Guide
6. in the file SETUP DOC To install PGP on your MSDOS system you have to copy the compressed archive PGP2 6 3i ZIP file into a suitable directory on your hard disk like C PGP and decompress it Installing on Unix is generally similar to installing on MSDOS but you may have to compile the source code first A Unix makefile is provided with the source release for this purpose Setting up PGP to work with SDR After installing PGP you should modify your AUTOEXEC BAT file and make the SDR directory e g On MS DOS mkdir c SDR SDR Add the following line to your Autoexec bat set path c iwindowsS c PGP set home c isdr set PGPPATH c pgpkeys On Unix with csh mkdir SDR in your home directory setenv PGPPATH home SDR pgp If you already have a pgp directory containing the pub secring files then just make a link e g if your pgp directory is in home pgp then In s pgp SDR pgp If you have not run PGP before the first step after installation is to make a pair of keys for yourself by running the PGP key generation command pgp kg Read the RSA Key Generation section of the pgp manual There two type of the keyring pgp generated in your c SDR SDR pgp on PC or home SDR pgp one for storing private keys called secring pgp and the other storing public keys called pubring pgp These two types of key rings are the principal method of storing and managing public and private keys Rather than keep individual
7. vi SDR v 2 5 User Guide 1 Introduction SDR Multicast Session Directory v2 5 is a tool which assists the user in setting up and joining conferences SDR v2 5 differs from previous versions of SDR in that is supports secure conference announcement This means that it is possible to announce sessions to a specific group of people only It is also possible to have the actual conferences encrypted as well Conferences which have been announced using SDR are listed in the tool s main window see Figure 1 rather like a TV listings guide Encrypted announcements will not be listed in previous versions of SDR which do not support secure conferencing In the case of authentication the digital signature is checked and the encrypted sessions are decrypted for the right group gmo ntass bruce cs ucl ac uk New Calendar Prefs Help Quit Public Sessions P UAlberta Physics Channel 2 UAlberta Physics Channel 3 Ukema YC strategy UO Presents KKNU New Cou UO Presents KMGE Magic 94 Vall Vall Vall 7 UO Presents KRYM Altemati Vall Val UO Presents KWAX Classical UO Presents KWVA Campus F e USC CS dgroup VR conferent 4 USC CS dgroup VR conferent VINT private dX x509authentication x503 4 Private Sessions n desencpgpauth pgp des A Vgl pgpencauth pgp pgp X x509enc x509 vid x5 Sencauth x509 x509 Multicast Session Directory v2 5a3 Figure 1 S
8. 3 how to create MPSE and password and click on OK In the case of PSE this will display the owner of the PSE s distinguished name In the case of MPSE the distinguished name of all of the certificates in your MPSE are displayed In this case select the user who you would like to sign If your certificate is stored on Smart card then give the location of Smart Card and the password For more detail of using Smart Card see Appendix 1 Section 123 Sdr X509 Configure Information Please configure sdr with your PSE name and Pin Passphrase Figure 8 X509 configuration Window Encryption you can encrypt your announcement by clicking on the encryption and choose between the following options none PGP DES X509 None Results in a non encrypted plain session PGP Lists the Public Keys available for Encryption click on the user you want to send the encrypted session to The session is always encrypted also with the most recent key created on your Secret Key Ring This is so you are able to decrypt the announcement you have sent X509 If this is the first time you are using X509 the window in Figure 8 appears otherwise a list of Distinguished Names DN of those users for which you have the Public Key will appear Choose the user to whom you want to send the encrypted session The session is always encrypted for you and the chosen user In your SDR home directory a file pks als txt exists which includes the list of all D
9. 9 Kops Mbone The multicast capable backbone of the Internet It currently consists of a network of tunnels linking the islands of multicast capable sub networks around the world Multicasting Multicasting is sending audio video etc on the Internet in way which ensures that anybody who is interested in receiving the information can receive it but only people who are interested will receive it Think of it as being in between unicast like most telephone calls between two telephones only and broadcast TV the signals are sent to you whether you want to watch or not Multicast address Addresses used for multicast conferencing should be in the range 224 2 0 0 224 2 255 255 Note Multicast addresses must be agreed upon in advance of The multicast session either through e mail or phone or assigned using SDR Network congestion A condition in an IP network where the amount of traffic injected into the network is too great for the routers to handle and some packets are discarded NTE Network Text Editor NTSC National Television Standard Code The television encoding used in the U S A PAL Phase Alternate Line The television encoding used in Europe PCM 43 SDR v 2 5 User Guide Port Audio encoding standard Pulse Code Modulation 78 Kbps 8 bit u law encoded 8 KHz A UDP User Datagram Protocol number unique to the broadcast session and should be over 5000 Note The port number must be agreed
10. Figures FIGURE 1 SDR V 2 5 MAIN WINDOW FIGURE 2 SDR DAILY LISTINGS WINDOW FIGURE 3 SDR DAILY LISTINGS WINDOW SHOWING SESSIONS ON 9TH JUNE FIGURE 4 SDR SESSION INFORMATION WINDOW FIGURE 5 SDR SESSION INFORMATION WINDOW INVITE BOX OPEN FIGURE 6 SDR SESSION INFORMATION WINDOW DETAILS DISPLAYED FIGURE 7 A SDR CREATE NEW SESSION WINDOW FIGURE 8 X509 CONFIGURATION WINDOW FIGURE 9 DES PASSWORD WINDOW FIGURE 10 SDR QUICK CALL WINDOW FIGURE 11 SDR MAIN WINDOW SHOWING PRIVATE SESSIONS FIGURE 12 SDR PREFERENCES WINDOW SESSIONS FIGURE 13 SDR PREFERENCES WINDOW INTERFACE FIGURE 14 SDR PREFERENCES WINDOW TOOLS FIGURE 15 SDR PREFERENCES WINDOW WEB FIGURE 16 SDR PREFERENCES WINDOW YOU FIGURE 17 SDR PREFERENCES WINDOW SECURITY FIGURE 18 SDR CREATING DES ENCRYPTION KEY WINDOW FIGURE 19 PASSPHRASE USED TO DECRYPT THE KEY FILE AND DES ENCRYPTED SESSIONS FIGURE 20 SDR V2 5 MAIN WINDOW FIGURE 21 ADDING PGP PUBLIC KEY FIGURE 22 PGP PASSWORD WINDOW FIGURE 23 KEY GENERATION PGP X509 DES WINDOW FIGURE 24 GENERATING DES KEY FIGURE 25 MAIL AGENT NAME WINDOW FIGURE 26 COMP EXMH WINDOW FOR SENDING DES FIGURE 27 X509 KEY GENERATION INFO FIGURE 28 USING MAIL AGENT TO SEND X509KEYFILE FIGURE 29 PGP KEY GENERATION WINDOW FIGURE 30 PASSWORD FOR PGP RSA PRIVATE KEY FIGURE 31 USING MAIL SYSTEM TO SEND PGPKEYFILE FIGURE 32 USING SMART CARD FIGURE 33 CHECKING SMART CARD FIGURE 34 SMART CARD CONFIGURATION INFORMATION
11. M lt 0C1 J WS 8HEOCM E 1R 2 PL BY 61 712B2900HU 0245_D M271 6MCLB lt 6YHUIJG B amp 42M4000 L ISED_EWWESL 5S 58907 p amp 1 lt MKOFEDA_ U0P FH RRS 2288 8 tK98N gt TI 2807 gt BF 8 G8DN EB gt lt P MTM amp IOE lt OD Ds SEL SWIM S5YL lt VSROF SRL s LC52e07 8 5 B MOOKT lt 1F 8NI9C gt _OCPS7 D lt H gt gt 0L CG T W Z62 KS400K00 lt 35E 0 M3VDU 2T 8PNRE N lt 9Y gt YUT X gt 3L7 149 USD8 M lt 48 5U 0 6 80 HN3R 3 MI4QKM 1 gt ZILNFKI gt 484V 31UTIZAR KCE5M GXU SOTRO KSE SX HN38 4 4 J2 YP IS 2HO0BP FE S O SAMKD L M LYW PSD84 11ESX2 T Message saved Figure 28 Using Mail Agent to send x509keyfile Make PGP Key Clicking on Make PGP Key the window in Figure 29 will appear Follow the instruction on Figure 29 You need to type the RSA password which was used in Figure 29 again in Figure 30 This will create a file called pgpkeyfile in your SDR home directory which includes the password Public key and Private Key as shown in Figure 31 At present implementation this only works on Solaris on a PC you need to do it manually using pgp kg and follow the instruction displayed on your terminal When the keys are created you need to add the secret key and the public key and the password to your E mail message and send it 36 SDR v 2 5 User Guide y PGP Setup c 1990 96 Philip Zimmermann Phil s Pretty Good Software 1996 01 18 International version
12. X509 then the window in Figure 8 will appear Otherwise it will use the secret key from your PSE MPSE and decrypt the session If the session is encrypted with a Public key found in PSE MPSE then the decryption is a success Otherwise it fails and you do not see anything Note To use X509 set X509STATE on see Appendix 2 If you have the key which is used to encrypt the session in your key file then the decryption is a success otherwise it fails and you do not see anything 3 8 6 3 Viewing an authenticated and encrypted session The Main SDR Window contains a list of sessions authenticated and unauthenticated sessions in the top upper frame and encrypted sessions in the lower Frame of the window in Figure 20 These sessions are either on now or have been announced to take place sometime in the future An icon telling you which type of session it is precedes each session pm Is a broadcast i e the session is not interactive New users may join the session but they may not participate i e actively send audio and or video E Is a meeting i e an interactive session 32 SDR v 2 5 User Guide Pal Is a test session The sessions can be viewed by clicking on the required session in Figure 20 If the session is authenticated and or encrypted then there will be an Authentication Info button and an Encryption Info button as shown in the window in Figure 4 and the icons will be the inverse of the above icons The foreground a
13. give you a list to choose from Group Chat Small Meeting and Large Meeting Again this is only to inform the people you are going to invite of your intent for the session e Area Heached allows you to specify how far you would like your session to reach Local Scope will keep your session roughly within your campus or site Hegion covers approximately a continent and World will make your session world wide e Next you have to select which media you need for your quick call The media available are audio video whiteboard and text The corresponding software tools could be RAT VIC WB not available for Windows95 NT4 0 and NTE By default audio is selected You can select or deselect the media by clicking on the buttons on the left with a cross or a tick on them When a media has been selected the field with the name 21 SDR v 2 5 User Guide of the medium becomes a button Clicking the button will give you a list of options applicable to that specific medium These are the same as for setting up sessions Audio Receive Only Mode Use this when creating a session of the type broadcast Packet size You can chose between 20ms 40 ms or 80ms You generally do not need to alter this Video There are no options for video Whiteboard You can select the orientation of the WB Portrait Landscape and Upside down Landscape depending on what you want to use the whiteboard for Sometimes imported postscript images will appear
14. is normally used with two different DES Keys and then has an effective key length of 112 bits 1 2 Public Key Cryptography Public Key Cryptography PKC solves many of the data exchange problems of symmetric key cryptography Public key cryptography uses a pair of keys that are related mathematically One of the keys is made available to the public and the other is kept private Messages that are encrypted with the public key can only be decrypted with the private key hence this mechanism is asymmetric Public key cryptography also provides the ability to digitally sign a message A digital signature electronically verifies the identity of a data sender and the integrity of the data itself Two popular software packages which are based on PKC are PGP and Secude 1 2 1 PGP 2 6 Pretty Good Privacy tm PGP from Network Associates is a high security cryptographic software application for MSDOS Unix VAX VMS and other computers PGP allows people to exchange files or messages with privacy authentication and convenience PGP is based on public key cryptography PGP combines the convenience of the Rivest Shamir Adleman RSA public 46 SDR v 2 5 User Guide key cryptosystem with the speed of symmetric cryptography It uses message digests for digital signatures data compression before encryption good ergonomic design and sophisticated key management PGP uses message digests to form signatures A message digest is a 128 bit c
15. keys in separate key files they are collected in key rings 52 SDR v 2 5 User Guide to facilitate the automatic lookup of keys either by key ID or by user ID Each user keeps his own pair of key rings An individual public key is temporarily kept in a separate file long enough to send to your group each member of which will then add it to their key ring You can use pgp kx to extract a key from your keyring and pgp ka to add a key to your key ring To see a quick command usage summary for PGP just type pgp h 2 2 Secude This can be obtained from hitp www darmstadt gmd de secude If you want to receive or send x509 authenticated and encrypted sessions then set X509STATE on in your environment This can be done by On PC Add the following line to your Autoexec bat set X509STATE on On Unix if you are using the C Shell Add the following line to your cshrc setenv X509STATE on If the XBO9STATE is set in the environment then you need to download and install Secude on your system Installing Secude Secude formerly SecuDE Security Development Environment is a security toolkit that incorporates well known and established symmetric and public key cryptography It offers a library of security functions security APIs and a number of utilities Installation after downloading Secude from Darmstadt XXXXX follow the instruction in the readme file To use Secude with SDR you need to add the location of Secude to your
16. minutes the maximum is 4 weeks Finally if your session is to be repeated e g weekly you need to select how many weeks it is going to be repeated for e Note Your session will only be announced in SDR when you are running SDR yourself i e if you quit SDR the session disappears from all other people s SDR until you restart your SDR 4 Click next on Figure 7c Figure 7d will appear rj Sdr Create New Session Step 3 Select the Distibution Scope You need to decide how far away you wish the traffic from this session to be received You can set this using TTL scoping or Admin Scoping TTL Scoping is the old method we recommend Admin Scoping Area Reached Local Scope Region ttl 63 World ttl 127 Back Next gt gt Accept Cancel Figure 7d e Area Reached allows you to specify how far you would like your session to reach Local Scope will keep your session roughly within your campus or site Region covers about a continent and World will make your session available world wide Admin scope is a more accurate way of scoping than 15 SDR v 2 5 User Guide using TTL and should be used whenever possible Talk to your local network manager about implementing admin scope 5 Click on next On Figure 7d Figure 7e will appear r Sdr Create New Session Step 4 Choose and configure the media You need to decide which media the session will use For each medium you need to
17. path environment ON PC As Secude comes with a licence agreement printout it is not useable on PC with sdr But you can get a version of secude without the licence agreement from UCL Edit Autoexec bat and add the Secude directory to your path On Unix 53 SDR v 2 5 User Guide Add the Secude home directory to your path 2 3 Tcl and Tk Library SDR requires the use of Tcl Tk SDR has been tested with Tcl Tk v8 and this version should be downloaded from http www scriptics com and installed You will need to have two programs to execute Tcl Tk scripts tclsh a command shell for Tcl only scripts and wish which is like tclsh but includes the Tk widget Depending on your platform Unix or PC download from the above URL e Installing Tcl Tk on Windows95 NT4 0 The easiest way to get started with Tcl Tk is to install it under Windows95 NT4 0 Just follow the steps on the download page and download the self extracting binary Once it has finished downloading double click on the file you received to start the self extraction process e Installing Tcl Tk on UNIX Follow the instructions on the download page For UNIX you must download the source code and run make Full instructions are included in the tcl release 54
18. upside down in the whiteboard and the Upside down Landscape mode is needed in order to see the images the right way round The whiteboard normally starts up in receive only mode In order to have it start up in a mode where you can write as well you need to select the Send Receive Mode Text There are no options for text For each medium you can select the format where applicable Audio The formats available are PCM DVI GSM LPC and Redundancy If all participants in the session are using the audio tool RAT as opposed to VAT you should select Redundancy If some of the participants are using the audio tool VAT you should select DVI Video The formats for video are H 261 nv M JPEG and Cell B Please note that the H 261 used by VIC is called intra H 261 and is not a complete implementation of H 261 Whiteboard There is only one format for whiteboard 22 SDR v 2 5 User Guide Text There is only one format for text SDR will automatically allocate addresses and port numbers to the media e As opposed to creating a session you invite people for a quick call A quick call can be thought of in the same terms as a phone call you do not announce a phone call beforehand It is less formalised than a pre announced session The Invite button expands the Session Information Window to contain a box for inviting other SDR users to join the quick call See Figure 5 In order to invite other SDR users y
19. 2 5 User Guide Press Accept and this will set and send your session You can amend the information by using Back buttons Cancel will abort and lose any information you have entered 3 7 Making a Quick Call Session Name Expected Duration Media Format Layers Encryption 5 mins Yl 44 audio e law kz JE as Purpose Group Chat X e video Local Scope EX Region ttl 63 Xj text World til 127 Invite Cancel Figure 10 SDR Quick Call Window z Area Reached xI whiteboard r FO Setting up a quick call is very similar to creating a new session The main difference is that the session will only be announced to people whom you invite If they accept the invitation the session will appear in both yours and their Main SDR Windows under Private Sessions see Figure 20 At present you can not authenticate and encrypt session invitation this is planned to be implemented in later stage The following procedure must be followed e You must give the session a name e You can select the Expected Duration of the session by clicking on the 5 mins button which will then give you a list to choose from This will not affect the session Selecting an expected duration is only to inform the people you invite of how long they can expect the quick call to last e You can select the Purpose of the session by clicking on the Group Chat button which will again
20. Combustion Collaboratory Film Scouts Multicast IDMAPS Private IMJ Channel 1 Private Sessions Multicast Session Directory v2 4abi Figure 11 SDR Main Window Showing Private Sessions 3 8 SDR Preferences Window In this section we shall go through all the options that SDR offers Press Cancelto undo any changes that you may have made in the Preferences Window since you last pressed Save Preferences or Save amp Apply Preferences Press Apply Preferences to accept the changes you have made in the Preferences Window The changes will only apply for this particular SDR session Next time you start up SDR the preferences will be as before Press Save amp Apply Preferences to accept the changes you have made These changes will apply for all uses of SDR until the preferences are changed again 3 8 4 SDR Preferences Window Sessions It is possible to customise the list in the Main Window to show only preferred sessions each session can be marked as preferred or not current sessions and future sessions To achieve this click the Preferences button in the Main Window and select the appropriate option in the Preferences Window Sessions see Figure 12 This window also allows you to hide test sessions If you select Preferred sessions you can choose which sessions are to be listed by hiding the sessions you do not want listed in the list of sessions in the right hand side of the Preferences
21. DR v 2 5 Main Window More information about each session can be obtained by clicking on its name in the list A window will appear with further details about the event security information and an invitation to join When you join a conference using SDR the appropriate tools for that session will automatically be started up on the right addresses and with the right parameters Alternatively the user may decide to start up only a few of the tools Not only the session announcement SDR v 2 5 User Guide but also the session itself may be private this is ensured by enabling the tools to encrypt the data stream with a pass phrase The pass phrase may be entered automatically or through SDR With SDR anyone can create and advertise their own secure conferences and invite other people to join if they wish It provides a framework for setting up secure conference session announcements and automatically configures the relevant tools Once a conference has been set up it will be announced to other users of SDR for a certain period of time usually specified by the organiser of the conference During this period other SDR users can join the session If they have the appropriate keys they can check the authentication and decrypt the session It is also possible to invite someone for a quick 5 minute consultation or a full meeting like making a phone call SDR can receive and send encrypted and authenticated session announcements using technology
22. IC is the main factor in the correction equation they use l 256 powdl 256 0 gamma where is the intensity of the red green or blue component and I is the corrected form The curve is knee shaped the lower gamma the sharper the knee more contrast Audio encoding standard ITU video encoding standard IP address JPEG IP Internet Protocol addresses are unique numerical identifiers for each networked host computer The IP address is used in conferencing when the conference is point to point rather than multiparty Video encoding standard for still images It has a high compression rate it computes by dithering and losing unnecessary information hence considered lossy Decoding speed can be traded off against image quality Kilobits per second Kbps The Kops rate enables the participants to track how much bandwidth is being used during a session For videoconferencing the Kbps should not be raised above 128 Kbps unless using a point to point conference or a Local Area Network ITL 16 See TTL Lecture mode An optimisation for one way transmission which increases the delay on the layout of the media in order to minimise the loss of data in the network The longer the playout is delayed the more time there is to retransmit lost packets Loss Rate The percentage of packet information lost during transmission 42 SDR v 2 5 User Guide LPC Audio encoding standard Linear Predictive Coder
23. Ns for which you have the public key in PKList If you receive a certificate and add this to your PSE manually then you should also add the DN to this file This is done automatically when you receive an authenticated session the 19 SDR v 2 5 User Guide Esar Enter the pass phrase for your key file public key is added to your PSE MPSE and the DN of the sender is added to pks als txt Note To use X509 you should set X509STATE on see Appendix 2 You must enter your passphrase to i able to load your encryption eys Password OK Cancel DES Figure 9 DES Password Window If you have not entered your passphrase in the SDR main window Figure 20 then the window in Figure 9 will appear requesting the passphrase to decrypt the keys clicking on OK will list the available DES Keys If you have already entered the pass phrase in Figure 20 when you started SDR the list of keys will appear that has been created using the Pref Security window Click on the key that you want to use to send a symmetric encryption session 8 Click next on Figure 7g Figure 7h will appear r Sdr Create New Session entered Check the details below are correct If they are correct press Accept If they re incorrect go back and amend the infonnation Cancel will abort and lose any infonnation you ve Review session details Next gt gt Accept Cancel Figure 7h 20 SDR v
24. SO9STATE is set see Appendix 2 then the window in Figure 32 will appear Click YES and the window in Figure 33 will appear Clicking OK the window in Figure 34 will appear After filling the required information the secret ring file secring pgp will be encrypted using the Smart Card and a file secring enc will be created in SDR home directory and the secring pgp will be deleted Clicking NO will end SDR without changing anything SMARTCARD Would you like to use smart card to encrypt your PGP secring file YES NO Figure 32 Using SMART CARD 39 SDR v 2 5 User Guide ka SMARTCARD Piace your smartcard OK NO t Figure 33 Checking Smart Card Sdr SMART CARD Configure Information Please configure sdr with your SMART CARD PSE name and Pin Passphrase SMART CARD Location smartcard pse PIN for SMARTCARD Figure 34 Smart Card Configuration Information 4 Known Bugs Not all announced sessions are displayed in the Calendar Daily Listings Window You cannot use x509 and Smart Card at the same time on Solaris 40 SDR v 2 5 User Guide Glossary Bandwidth A term used to show the amount of information flowing through a communications channel Expressed in units of n x1000 bits per second Kbps CIF Common Image Format fitting an image into dimensions of 352x288 pixels Codec COder DECoder Converts analogue signals to digital signals and VICe versa CODECs are used for c
25. Tue Wed Thu Fri Sat 1 L2 3 ca te tm Bel 8 So 4 5 6 7 8 12 13 14 15 16 17 11 12 13 14 15 19 20 21 22 23 24 18 19 20 21 22 26 27 28 29 30 31 25 26 27 28 29 Dismiss Figure 2 SDR Daily Listings Window The Daily Listings Window see Figure 2 displays sessions on a daily basis like a TV guide Clicking on the Daily Listings button in the Main Window will open the Daily Listings Window Days displayed in blue and enclosed in a box are days for which sessions have been scheduled To see the sessions for a particular day click on the date and the window expands to show the sessions for that day see Figure 3 You can open as many days as you like at the same time You can close the listings for a day by clicking on the Hide date button in the top right hand corner of the box displaying the listings for that day SDR v 2 5 User Guide ex Sdr Daily Listings Click on a day to show what s on June July Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat To 225 0354025936 August L2 3 41 7 8 L5 L6 L7 3 10 11 4 5 6 4 12 13 14 15 16 17 18 11 12 13 14 19 20 21 22 23 24 25 18 19 20 21 26 27 28 29 30 31 25 26 27 28 30 31 Sessions on Tuesday 3th June Click on a session to see details of it Hide 9 June 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 EIE FEET Ed Rh ARARA a E E GG E E Enc FAT EE MIELE EA DR E s t RES ER RR TH BAR ee BE tt tear Test ATRN A epee
26. User Guide something unwieldy such as ucacimt If you provide a SIP Alias they can use that although the hostname still has to be added to the Alias The SIP Server URL functionality has not been implemented yet When it is you will be able to enter the name of a local machine which listens to SIP requests in order to forward them to another location This means that you do not have to know on which machine the person you want to invite is currently working ka Sdr Preferences Help mode 9 Balloon Help Sessions Interface Tools Web You People Security Your Name Email Address and Phone Number Name Goli Montasser Kohsari Email gmontass cs ucl ac uk Phone iei 71 380 72115 A SIP alias is a name people can put in a session invitation to call vou Normally they will use your username but if you want sdr to answer calls addressed to a more human readable name you can add it here You cannot add another valid username SIP Alias SIP Server URL These will be added to sessions you create so people can contact you if there is a problem Cancel Apply Preferences Save amp Apply Preferences ae Figure 16 SDR Preferences Window You 3 8 6 SDR Preferences Window Security In order to encrypt your session using DES you need to generate DES keys The following section shows how to g
27. User Guide for SDR v2 5 29 September 1998 Version 15 DRAFT University College London Computer Science Department SDR v 2 5 User Guide Acknowledgements This user guide is based on the UKERNA SHRIMP User Guide which will be available from http www ja net service_development video service_developments shrimp index html The current document has been updated to incorporate security which is now part of SDR Disclaimer UCL cannot accept any responsibility for any loss or damage resulting from the use of the material contained in this document The information is believed to be correct but no liability can be accepted for any inaccuracies SDR v 2 5 User Guide Copyright note SDR Copyright c 1995 1996 1998 University College London All rights reserved Redistribution and use in source and binary forms with or without modification are permitted provided that the following conditions are met 1 Redistributions of source code must retain the above copyright notice this list of conditions and the following disclaimer 2 Redistributions in binary form must reproduce the above copyright notice this list of conditions and the following disclaimer in the documentation and or other materials provided with the distribution 3 All advertising materials mentioning features or use of this software must display the following acknowledgement This product includes software developed by the University of Califor
28. Window Sessions Sessions marked 24 SDR v 2 5 User Guide visible will be displayed in the Main SDR Window You can also hide sessions by clicking on them with the right mouse button in the Main SDR Window The Interface tab in the Preferences Window allows you to choose to have the sessions listed by type broadcast meeting test rather than alphabetically And you can choose not to have the type displayed at all Help mode 9 Balloon Help Sessions Interface Tools Web You Security Show which sessions Berkeley Multimedia and Grap visible y Canadian Radio visible all sessions CDT Ellemtel private visible CERN ATLAS visible w preferred sessions IDMAPS Private visible A IMJ Channel 1 visible D GORI TS IMJ Channel 2 visible future sessions ISI UO session visible Java Science Tools Workshop visible Additional filters Kazimodal traditional band visible LabWeb The Spectro Micro visible Hide test sessions MBone RTP Audio visible NASA Leaming Technology visible NASA LeRC Protocol Group p visible Places all over the world visible kd Cancel Apply Preferences Save amp Apply Preferences wwa aa A Figure 12 SDR Preferences Window Sessions 3 8 2 SDR Preferences Window Interface You can select normal or technical interfaces for creating and viewing sessions in the SDR Preferences Window Interface see Figure 13 The technical interface for cr
29. ady running and you would like to use it for displaying web pages e Select Start web browser if you want to use Mosaic or Netscape and if you want SDR to start up the web browser automatically when required e Select the third option if you would like to use SDR s built in web browser If need be you can enter a proxy A proxy is a computer used as a web cache You should ask your local systems administrator for your local proxy e fyou want to use another web browser altogether you can select Add URL to Clipboard and subsequently paste the contents into a web browser of your choice Help mode 9 Balloon Help Sessions Interface Tools Web You Security Web Links Use web browser already running w Start web browser Netscape Use sdr s built in web browser Proxy in the form host port Add URL to clipboard Cancel Apply Preferences Save amp Apply Preferences Figure 15 SDR Preferences Window Web 3 8 5 SDR Preferences Window You You can enter your name email address and telephone number in the SDR Preferences Window You see Figure 16 These are the default values used by SDR when creating a session You can also provide a SIP alias A SIP alias is just another name that other participants can use when inviting you to join a session or a quick call If you do not provide a SIP Alias they have to use your username which might be 27 SDR v 2 5
30. aily Listings Window for the relevant day This bug does not effect the basic functionality it will be fixed but has low priority SDR v 2 5 User Guide Joining a session There are two ways of joining a session Click on any of the sessions listed in the Main SDR Window see Figure 1 or in the Daily Listings Window see Figure 2 This will cause a Session Information Window to be opened see Figure 4 Check that the session is supposed to be on and join by clicking the Join button in the bottom left hand corner This will start up all the tools needed to join the session The other and quicker way of joining a session is by clicking with the middle mouse button or by clicking both mouse buttons at the same time on a two button mouse if using Linux or by holding the Ctrl key down on the keyboard while left clicking on the mouse if using Windows95 NT4 0 on a session name in the Main SDR Window This will start up the tools without bringing up the Session Information Window You should now be able to see what sessions are on and join them For information about how to create your own sessions how to make quick calls and how to customise the interface see the SDR User Guide below 3 SDR User Guide 3 1 Help You can access the help system at any time from the Main SDR Window or from the Create New Session Window 3 2 Balloon help In the Main Help Window and in the Preferences Window you can switch balloon help on and off
31. ane Gee EE AREE ZI EE wee EE EE ICE 3 L HNANOG 13 feedback whitebo R OM MS ER ME ER ADEE ENED EE al I ES Cae NASA Space Shuttle Missi Eu Es Fe Ee E ec d e Ee EF EAIEJEJ EHERERH ERIE pen OneCall Presents WHJE TeleEducation NB UAlberta Physics Channel 1 SEE ieee m md EE A D Secs fet T e e m n m e SSS SS T Se ae AAA K Dismiss Figure 3 SDR Daily Listings Window Showing Sessions on 9th June The lines to the left of the session names indicate when the session will be on If the line goes all the way across the session is continuous If the sessions are shorter lines the end of the lines indicate what time the session will be on The session kre s wb for example has been announced to take place between 3 p m to 6 p m amp Even if a session is advertised to take place this does not guarantee activity 3 4 Joining a session Joining a session just means starting up the tools used for the session on the right addresses and in the right format A meeting between research partners in Europe will typically make use of audio video and a text editor The one who calls the meeting will announce the session in SDR Come the time for the meeting all participants can join the session through SDR which will automatically start up the right tools on the right addresses Joining a session from the Main Window The easiest way to join a session is by clicking on the session
32. but they may not participate i e actively send audio and or video E Is a meeting i e an interactive session a Is a test session Secure test broadcast and meeting icons are the negative image of test broadcast and meeting icons Generation of Group Keys In order to encrypt and authenticate a session you will need to have the right keys Generating and sending group keys can be done automatically in SDR by 1 Establishing a group membership with an e mail list SDR v 2 5 User Guide 2 Generating group keys See section 3 8 6 5 3 Sending group keys to group member See section 3 8 6 5 Receiving group keys This is done manually In order to see sessions that are encrypted and authenticated you need to have the right keys in your SDR Environment If you receive e mail containing the key information you need to store it in the right place for SDR to use it automatically For example for PGP the public key should be added to the public key ring and the secret key should be added to secret key ring Using a Smart Card You can use a Smart Card as your private identification to encrypt and decrypt the repository access list information which contains the secret keys and public keys Or you can use it for authenticating a session using the Certificate on your smart card In the present implementation of SDR a Smart Card can be used to encrypt the PGP secret key ring This is done when you quit SDR If the secret ke
33. choose the protocol and format Some formats also let you choose the number of layers in the encoding Media Format Layers Encryption A audio law kHz 1 4 X a video X whiteboard E X text 4 lt lt Back Next gt gt Accept Cancel Figure 7e e Next you have to select which media you need for your session The media available are audio video whiteboard and text The corresponding software tools could be RAT VIC WB and NTE WB is not available for Windows95 NT4 0 A WB clone WBD which is compatible with WB but has less functionality and is less stable is available for Windows95 NT4 0 By default audio is selected You can select or deselect the media by clicking on the buttons to the left with a cross or a tick on them When a tool has been selected the field with the name of the medium becomes a button Clicking this button will give you a list of options applicable to that specific medium These are Audio Receive Only Mode Use this when creating a session of the type broadcast Packet size You can chose between 20ms 40 ms or 80ms There is generally no need to alter this Video There are no options for video Whiteboard You can select the orientation of the WB Portrait Landscape and Upside 16 SDR v 2 5 User Guide down Landscape depending on what you want to use the whiteboard for Sometimes imported postscript image
34. d to configure when the session will be active so people will know when to join it For example if the session is active on Monday and Thursday each week for four weeks configure Monday s start time and duration in the first row Thursday s start time and duration in the second row set both to be Weekly and configure Repeat for to be 4 weeks how often it takes place when it first takes place how long each time Once from Wed 26 Aug at 10 00 for 2hours 5 Session will take place Length of this series of sessions eer Repeat for Back Next gt gt Accept Cancel Figure 7c normal interface Next you should set when the session is going to be on 14 SDR v 2 5 User Guide Click on the Once button and you will get a menu with the following items Once Daily Weekly Every Two Weeks the two greyed out options Monthly by Date and Monday through Friday are not yet available Select the one appropriate for your session Next you select the date when your session is going to be on or the day of the first session if it is to be a regular event by clicking on the up or down arrows next to the from field You then select the time when the session is due to begin by clicking on the up or down buttons next to the at field You then select how long you think the session will go on for by clicking on the up or down arrows next to the for field The minimum is 30
35. ddr 239 255 216 20 Port 25408 TTL 15 Vers ptime 40 Format H 261 Proto RTP Addr 239 255 57 41 Port 56944 TTL Format wh Proto udp Addr 239 255 146 23 Port 42795 TTL 15 15 Dismiss the Format UCL N Proto udp Addr 239 255 47 128 Port 49764 TTL Heard from 128 16 8 183 at 16 Jun 98 10 13 BST Allows you to invite other sdr users to take part in the session 15 session Record the session Edit the session information creator only Figure 4 SDR Session Information Window SDR v 2 5 User Guide The Session Information Window gives the following information about the session The icon in the top left hand corner will tell the type of session PI broadcast F4 meeting or 4 test If you click on the icon it will describe the session type in words To the right of the icon is the name of the session followed by type of security and if it is authenticated the type used to authenticate PGP or X 509 and if it is encrypted the type used to encrypt PGP X 509 or DES The box underneath the name contains a short description of the session The box underneath the description tells you when the session is going to be on Sessions can be on just once for a couple of hours or for a set period of time and so on The Authentication Information button expands the Session Information Window to include a box giving you the authentication Inf
36. dow A X x509enc x509 kd 30 SDR v 2 5 User Guide 3 8 6 2 Receiving Encrypted Authenticated sessions Authenticated Sessions PGP Fri If you have the Public Key of the user who signed the payload then the Authentication is a success if not the authentication fails Adding Public Key Would you like to add Public key of newgroup1 to your public key ring YES NO PGP CERT X509 Figure 21 Adding PGP Public Key if you have the Public Key of the user who signed the payload and the signature is verified then the Authentication is a Success Otherwise the Certificate received is used to check the signature After checking the authentication using the received public key Figure 21 will appear Clicking Yes will add the received Certificate the Public Key ring This key can be used subsequently as an untrusted key for checking authenticated sessions and sending encrypted session If you have not already configured SDR with X509 information then the window in Figure 8 will appear allowing you to enter the PSE MPSE location and the passphrase Then if your PSE has the public key of the sender and the signature is verified the authentication will be a success otherwise it fails Note1 To use X509 set X509STATE on see Appendix2 Note2 there is a bug in Secude software which means that you always have to send the certificate with the signed data Consequently X509 always sends the certificate and se
37. e 40 gt video Format H 261 Proto RTP Addr 239 255 51 234 Port 54856 TIL 15 K4 whiteboard Format wb Proto udp Addr 239 255 237 250 Port 37993 TIL 15 Be text Format UCL K Proto udp Addr 239 255 122 13 Port 58426 TIL 15 Heard from 128 16 8 183 at 26 Jun 98 13 20 BST Join Invite Record Edit Delete Dismiss Figure 6 SDR Session Information Window Details Displayed SDR v 2 5 User Guide 3 6 Creating a Session Announcement s Sdr Create New Session Step 0 Information About the Session You need to give a title to your session and provide information about it The information should be a paragraph or so describing the purpose of the session If you need to refer people to more information add a URL below The URL can be left blank but the title and information must be given When you ve filled in this information click on Next Session Name testsecurity Description The pay load is signed by Goli using pgp and encrypted for goli and Edmund using X509 URL Test URL Back Hext Accept Cancel Figure 7 a SDR Create New Session Window You can create your own session by clicking on the New button in the top left hand corner of the Main SDR Window This will bring up a small menu with two options Choose the Create advertised session option and you will get the Create New Session Window that you see in Figur
38. e 7 This is what you must do 1 On Figure 7a do the following e Give the session a name e Type in a description of the session e f you would like to provide a link to a web page for further information about the session type in the URL an example of an URL is http www cs ucl ac uk in the field provided You can check if the URL is correct by clicking the Test URL button to the right of the URL field This will start up a web browser with the URL you have provided The Test URL button will in effect do the same as the More Information button in the Session Information Window once the session has been created 2 Click next on Figure 7a Figure 7b will appear 13 SDR v 2 5 User Guide Sdr Create New Session Step 1 What Type of Session is this You need to specify the type of session Use broadcast for sessions that are largely non interactive meeting for interactive sessions and private meetings and test for anything that isn t intended for real listeners Type of Session Test lt lt Back Next gt gt Accept Cancel Figure 7b e Click on the Test button to select the type of session desired You will get the choice of Test Meeting and Broadcast This is for the information of other users only no settings will be affected 3 Click on next on Figure 7b Figure 7c will appear r Sdr Create New Session Step 2 When will the session be active You nee
39. e ac uk Note that this is not the email address of John Smith but his username followed by the address of the computer on which he is currently working e There is an address book to which you can add people that you often invite Press Browse to browse existing entries in the address book and to add new entries e When you invite another SDR user a window will pop up on his or her screen informing them that they have been invited this particular session it will provide the information available in the Session Information Window and ask them to accept or reject the invitation Subsequently you will get a window popping up on your screen saying whether your invitation has been accepted or rejected You can invite as many people as you like to take part in a session 10 SDR v 2 5 User Guide Quick Call Group Chat Session will take place from 14 03 to 14 06 GMT on 20 November 37 Contact a Media Details Details Invite user usemame hostname Browse Invite Join Record Edit Delete Dismiss Figure 5 SDR Session Information Window Invite box open The session invitation is not encrypted such encryption will be implemented in a later version of SDR If you receive an encrypted message you can still invite another user who does not have the encryption key to join the session e In principle the Record button allows you to record the sessions digitally This function has be
40. eating sessions gives you more options in the Create New Session Window and the technical interface for viewing sessions displays media details as default as opposed to having to press the Media Details button to display them Long and short labels apply to button names If you chose short labels the Main SDR Window will be smaller thus taking up less space on the screen This might be desirable if you have SDR running all the time Session Listing refers to the list of sessions in the Main SDR Window By default they are listed alphabetically If you select List by Session Type type or category will list sessions All meetings will be listed together all broadcasts will be listed together and all test sessions will be listed together By deselecting the Show session type you can choose not to have the icons showing the session type displayed 25 SDR v 2 5 User Guide Help mode 9 Balloon Help Sessions Interface Tools Web You Security Interface Style Create Session View Session Label Detail Normal Interface Normal Interface Long labels beginnner mode w Technical Interface w Technical Interface Short Labels expert mode Session Listing List Alphabetically wv List by Session Type E Show session type Cancel Apply Preferences Save amp Apply Preferences Figure 13 SDR Preferences Window Interface 3 8 3 SDR Preferences Window Tools The
41. en implemented for a specific recorder MMCR Because recording functionality is independent of SDR the SDR is shipped with its record button not enabled The release of MMCR includes a protocol to enable the record button e Dismiss closes the window e If you have created the session yourself you will have in addition a Delete button which will delete the session announcement The session announcement will disappear immediately from your own screen but it may take a few minutes before it disappears from the screens of other SDR users e If you have created the session yourself you will also have an Edit button which brings up a window where you can edit the details of the session The Edit Window is very similar to the Create New Session Window described below see Figure 7 MMCR Multicast Multimedia Conference Recorder is a recording tool for recording and playing back multicast conferences The tool is being developed at UCL 11 SDR v 2 5 User Guide Sdr Session Information Test session using X509 for digital Sugnature and PGP for Encryption E Z Session will take place from 13 00 to 15 00 BST on 26 Jun 36 Created by gmontass bruce cs ucl ac uk 64 Goli Montasser Kohsari lt gmontass cs ucl ac uk gt lt Goli Montasser Kohsari 0171 38072115 Session announced using sdr v2 5a3 A audio Format PCM Proto RTP Addr 239 255 253 136 Port 18014 TTL 15 Vars ptim
42. enerate DES keys 28 SDR v 2 5 User Guide 3 8 6 1 Generating DES Key Figure 17 SDR Preferences Window Security Click on the Add encryption group button and the window in Figure 18 will appear Name of encryption group Encryption key at least 8 characters Encryption key again Figure 18 SDR Creating DES Encryption Key Window Fill in the information and then Click OK If you have not set a passphrase then the window in Figure 19 will appear After setting up the passphrase for decrypting your key files and looking at Decrypted sessions the group name will appear in the window in Figure 17 29 SDR v 2 5 User Guide Figure 19 Passphrase used to decrypt the key file and DES encrypted Sessions Figure 20 shows the main window that appears after the passphrase has been set next time you start SDR You need to type the passphrase to view DES encrypted sessions ii gmontass bruce cs ucl ac uk New Calendar Prefs Help Quit Public Sessions F Ukema VC strategy 7 UO Presents KKNU New Coun 7 UO Presents KMGE Magic 94 7 UO Presents KRYM Alternativ 7 UO Presents KWAX Classical F F UO Presents KWVA Campus R Pa upgpauthentication pgp P 4 USC CS dgroup VR conferenc 4 USC CS dgroup VR conferenc F VINT private M x509encauth x509 x509 Enter passphrase to view encrypted sessions Multicast Session Directory v2 5a3 Figure 20 SDR v2 5 Main Win
43. er the Internet The standard values are 16 Site 47 UK 63 Europe 127 World Unicasting A unicast connection is a point to point connection between two specific machines VAT Visual Audio Tool WB Whiteboard 45 SDR v 2 5 User Guide Appendix 1 Security Technology Here we provide a brief introduction to some security mechanisms used in our implementation of SDR 1 1 Symmetric Encryption Symmetric cryptography uses the same key to encrypt and decrypt data Symmetric encryption is quite fast and is generally used when encrypting large amounts of data However it does not work well in situations where an individual would exchange encrypted data with more than a few people The problem is finding a secure and convenient way to exchange secret keys with all of the parties with whom one might communicate For this reason this type of cryptography by itself is not practical for a typical internet application The following are two of the more popular symmetric algorithms which are used in the above package or in the case of Triple DES might be so used in the future 1 1 1 DES The Data Encryption Standard developed in the 1970s by IBM is now widely used around the word DES uses a 56 bit key 1 1 2 Triple DES Triple DES is a variant of the DES algorithm that involves encrypting every session three times with the DES algorithm Triple DES has been shown to be significantly stronger than single DES It
44. escribed in this report is compatible with the Smart card supported by the present version of Secude 1 2 2 3 Multiple PSE The Multiple PSE file may be seen as a virtual directory containing all of your PSEs in one file This analogy is very close to the true nature of MPSEFiles as they really contain separate PSEs which do not share anything Every one has its own PIN and Key pair s Attached to each PSE in a MPSEFile is a label which should help you to remember the purpose for that special PSE PSEs in a MPSEFile are chosen by adding a so called selector to the MPSEFiles name Let us suppose for example that a MPSEFile mpse contains three PSEFiles that can be opened using the names mpse 1 mpse 2 and mpse 3 For the purpose of using the multiple PSEs in SDR you need to have the same PIN for all your PSEs Suppose you have three different PSEs group1 pse with password passgroup1 group2 pse with password passgroup2 and group3 pse with password passgroup3 The first activity is to change the password to your chosen password say passtest To change the password you do the following secude psemaint p groupl pse 49 SDR v 2 5 User Guide Enter PIN for groupl pse passgroupl PSE group4 pse gt chpin Enter old pin passgroupl Enter new pin passtest PIN changed passtest Reenter new pin Do the same for group2 and groups To create mpse do secude pseconv o mps M groupl pse group2 pse group3 pse This will c
45. estgroupi To amontass ucacewh ucacibr cct Subject PGP Information for group conference Feet sent mail Hime Versionz 1 0 Content Type text plain password group Type Bits KeuID Date User ID sec 512 62BC8C75 1998 06 18 testaroupi Version 2 6 3i LOEAA jWITEwAARECAK Ocprih 1y601WVr2eCZmD j64IFxV3w7P IVoj f6LS7 Qu g1TRIJ2abHhhzTu5hkMOFrTudTOm guFe2K8 jHUABRMBF j1q401bROEB askrZYT NkurQ2Cz3JYwsfUqLe qamykTt ji sC1HRG5eLKqpeuosU1Lv3dJL20b1CB1MYyB 21s3tNuxgEnNg3ABAGM4 xfFe 7dcLfFHz1B5N UDK514s22Pi 3ahaRfAMGdaAUBO W6k 1 a7UkdzGzzEQYYXTH UnT 1 KYh1HAH1Evghdj0D BSZ5wAdahJCMP5gYhfBE pbS5llCbm bDpR3isY5215kSQ8L kdGVzdGdubsVwh c4PG Type Bits KeuID Date User ID pub 512 62BC8C75 1998 06 18 testaroupi Version 2 5 3i mQBNA j JTBGwARRECRK Ocprih 14501WVr2eCZnD jb4 JF x Y3u7PY IVoj f6LS u g1TRIJ2abHhhzTuBhkHOF r TwdT mOguF e2K8 HUABROOCNR1c3Rnem31cDGJAFUC BRA1il tOguFe2K8jHUBRT JnRaCBZSZkbkuDUcvHV5cdus 0BIDB6 j5inrXR38FzB3 VMbT jZPtGFuS3o4 7XRSRONb dZpozRwX TwJuzuDGGST SWZUux 1 Message saved Figure 31 Using Mail system to send pgpkeyfile 3 8 6 6 Receiving and storing Key information When you receive key information through e mail then you should set up SDR according to the keys you have received The following keys can be sent using SDR DES The text part of your message contains the group name and the Encryption Key To store this information on SDR click on Prefs button in the Main SDR Window select
46. how to generate DES X509 and PGP keys and how to use your chosen mail system to send it to the group members Section 3 8 6 6 will show you how to store keys to be used by SDR 3 8 6 5 Generating Group keys You can generate group keys PGP X509 or DES by clicking on the Help button on the top frame of the Main SDR Window in Figure 20 This will bring up a small menu with two options Choose the key setup option and you will get the key generation Window that you see in Figure 23 33 SDR v 2 5 User Guide rj Key Generation Help Key Generation Make Des Key Make X509 Key Make PGP Key Dismiss Sdr allows you to conveniently use PGP or X503 to encrypt or sign your sessions and decrypt and check signatures on sessions you receive To To create group PGP Key Pair To start using PGP you have to create a key pair A key pair consists of a public key that you want to spread around and a private key that you don t want anybody else than yourself to have But ona conferencing system everybody in the group should have the public and private key to join the session The private key is protected by a password You should be very careful not to lose that password and not to let anybody get access to it PGP can offer a very high level of secunty but if people can read your file especially the file that contains the private key and kd Figure 23 Key Generation PGP X509 DES window The following describes cl
47. icking on each button for generating required Key Make DES Key Clicking on this button causes the window in Figure 24 to appear Fill in the required information and Click OK This will create a file called deskeyfile in your SDR home directory which has the Encryption group and the Encryption key information r Sdr Des Information to send to group Please enter name of encryption group and key Des Encryption group testgroup1 Encryption Key at least 8 character eeeeeeeee Encryption Key again ee e e e e e e e ee eee Figure 24 Generating DES Key After Clicking on OK the window in Figure 25 will appear you can use any mail system that can send the information securely and include the file deskeyfile to send to the group MAILAGENT n Please enter mail agent RU ak emen Figure 25 Mail Agent name window 34 SDR v 2 5 User Guide E g if you use the Exmh mail system with PGP then you have r Zcs research poda violet gmontass Mail drafts 227 Abart Save amp Quit PGP Hore Text Help Sign Send Pgp ction encryptsign rfc822 off originator Goli Montasser_Kohsari lt gmontassfics ucl ac uk gt t recipients Goli Montasser_Kohsari lt gmontass cs ucl ac uk gt Edmund lt ucacewh cs ucl ac uk gt Edmund lt ucacewh cs ucl ac uk gt Ian Brown lt I Browntcs ucl ac uk gt test5 To gmontass ucacewh ucacibr kirstein cc Subject Des Key information Fee sent mai
48. indow in Figure 22 appears for the first time choosing the Same Password And type in the password which you are using for your sdr pgp session When you receive pgp key then make sure that you change the password This can be done using pgp ke E g suppose you receive group1 secrte key with password group1 and group2 with password group2 then after adding the secret key to your key ring change the passphrase for both group1 and group2 to be the same say sdrpgppass gt pgp ke Pretty Good Privacy tm 2 6 31 Public key encryption for the masses c 1990 96 Philip Zimmermann Phil s Pretty Good Software 1996 01 18 International version not for use in the USA Does not use RSAREF Current time 1998 08 05 13 43 GMT A user ID is required to select the key you want to edit Enter the key s user ID groupl Editing userid groupl in key ring cs research poda violet gmontass pgp pubring pgp Key for user ID testgroupl 47 SDR v 2 5 User Guide 512 bit key key ID D35A2CB1 created 1998 06 25 You need a pass phrase to unlock your RSA secret key Key for user ID testgroupl 512 bit key key ID D35A2CB1 created 1998 06 25 Enter pass phrase Pass phrase is good Current user ID testgroupl Do you want to add a new user ID y N n Do you want to change your pass phrase y N y Enter pass phrase T Enter same pass phrase again Secret key ring updated
49. l Hime Versionz 1 0 Content Type text plain DES Encryption Key this is a testkey DES Encryption Group testaroupi Best Regards Goli HKKK K K K KKK ooo oko K K K KKK K K RAR RARER RAR RARER RRR oko Message saved Figure 26 Comp Exmh window for sending DES Make X509 Key Clicking on Make X509 Key button the window in Figure 27 will appear Fill in the required information and Click OK This will create a file called x509keyfile in your SDR home directory which has a uuencoded file containing the created PSE and the password as shown in Figure 28 This file can be included in your mail agent to be sent to the required group Note You need to set X509STATE see Appendix 2 Sdr X509 Configure Information you need a newname for PSE PSE name PIN for PSE PIN for PSE again DN name Figure 27 X509 Key Generation Info 35 SDR v 2 5 User Guide NEI Zcs research poda violet gmontass Mail drafts 227 E Abart Save amp Quit PGP More Text Help Sign Send Pgp Actiont encryptsign rfc822 off originator Goli Montasser_Kohsari lt gmontass cs ucl ac uk gt recipients Goli Montasser_Kohsari lt gmontasslcs ucl ac uk gt Edmund lt ucacewh cs ucl ac uk gt Ian Brown lt 1 Brown cs ucl ac uk gt test5 To gmontass ucacewh kirstein cci Subjecttsending X509 key Feet sent_mail Mime Version 1 0 Content Type text plain password test begin 600 psetest
50. lecting X509 CERT sends the whole certification path up to the root certificate X509 CERT If the certificate is sent and you do not have the Public key in your PSE MPSE PKList then the public key is added to PKList and the DN is added to the pks als txt file In the case of MPSE the public key is added to MPSE 1 i e your first PSE in MPSE Thus subsequent authenticated sessions from the same user will be a success if the signature is verified Encrypted Sessions PGP This requires the private keys to decrypt the message If you do not have the private key or wrong passphrase then the decryption fails and you do not see the session If you have 31 SDR v 2 5 User Guide X509 DES the private key for the public key that is used to encrypt the session then it will ask you for the password to use your PGP Private Key The window in Figure 22 will appear r Enter PGP password a Same Pass password for Goli OK Cancel Figure 22 PGP Password Window Entering the password and Clicking OK will display the decrypted session in the lower window of Figure 20 If you are using the same passphrase for all your secret keys see appendix 1 section 1 2 1 1 then choose Same pass lf your secret key ring is encrypted then a window appears requesting the location of Smart Card and password to decrypt the secret ring file For more detail see Appendix 1 Section 1 2 3 If this is the first time you are using
51. name in the Main Window with the middle mouse button or by holding both mouse buttons down at the same time on a two button mouse if using Linux or by holding the Ctrl key down on the keyboard while left clicking on the mouse if using Windows95 NT4 0 This will start up all the tools needed for that session Joining a session from the Session Information Window Another way of joining a session is through the Session Information Window see Figure 4 which can be accessed by clicking on a session name in the Main Window or on the session name or timeline in the Daily Listings Window SDR v 2 5 User Guide In the Session Information Window click on the Join button Starting tools individually You can start up the tools individually by clicking on the button corresponding to the tool you want to start up If only one tool e g audio is used in the session you must press Join to start up the audio tool 3 5 SDR Session Information Window Normal Interface Conference When the session will be on Information about which media are used address formats etc Conference Tide Description Authentication Session will take page from 10 00 to 12 00 BST off6 Jun 38 Delete the session Creator only Information Encryption information Starts up the tools used in this sessions Encryption Info More Information FCM Proto RTP A
52. nd background colours on the top of the window in Figure 20 frame have meaning For example it the colour is green then the authentication was successful if it is blue then there was no authentication if itis pink then the authentication failed The colour of text in the top frame of the window in Figure 20 shows the encryption status If it is red then the encryption was a success The text shows the type and status of encryption and authentication with the session name In Figure 4 the Encryption was PGP and a success and the authentication was PGP and trustworthy The public key was found in the public key ring file If it uses the certificate which was sent by the session then the status is integrity Clicking on the Encryption Information button will open the encryption information frame which will display the information on the key used for decryption Clicking on the Authentication button opens the authentication Information If you created a session yourself then you will be able to delete or edit the session as shown in Figure 4 3 8 6 4 Generating and Receiving keys Before you generate keys you need to get an e mail system which has the capability of sending information securely for example Exmh can send encrypted and authenticated text body part using PGP Eudora can send PGP and S MIME authenticated and encrypted messages Next you need to establish a group membership possibly with an e mail list Section 3 8 6 5 describes
53. nia Berkeley and the Network Research Group at Lawrence Berkeley Laboratory 4 Neither the name of the University nor of the Laboratory may be used to endorse or promote products derived from this software without specific prior written permission THE REGENTS AND CONTRIBUTORS AS IS AND ANY EXPRESS OR PROVIDE IMPLIED WARRANTIES INCLUDING THIS SOFTWARE IMPLIED WARRANTIES INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT INDIRECT INCIDENTAL SPECIAL EXEMPLARY OR CONSEQUENTIAL DAMAGES INCLUDING BUT NOT LIMITED TO PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES LOSS OF USE DATA OR PROFITS OR BUSINESS INTERRUPTION HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY WHETHER IN CONTRACT STRICT LIABILITY OR TORT INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE SDR v 2 5 User Guide Contents LANE 1114000 3 571 o i RODEO ZY EE EYE ETC 1 2 G tling Stane d o R O O O AR 2 J SDRUSer Guide use Cwi 5 RB eC EO EO A RP 5 3 2 Balloon help oer them boa oda eaa siue 5 3 3 Seeing what sessions are on eese ssec eee 5 SA Joining a SESSION a eoe eiecit Oe ld he edu ie lad tdk di 7 3 5 SDR Session Information Window Normal Interface 8
54. not for use in the USA Does not use RSAREF Current time 1998 06 18 17 32 GMT Pick your RSA key sizet 1 512 bits Low commercial grade fast but less secure 2 768 bits High commercial grade medium speed good security 3 1024 bits Military grade slow highest security Choose 1 2 or 3 or enter desired number of bits 1 Generating an RSA key with a 512 bit modulus You need a user ID for your public key The desired form for this user ID is your name followed by your E mail address enclosed in lt angle brackets gt if you have an E mail address For example John Q Smith lt 12345 6789 compuserve com gt Enter a user ID for your public key testaroupl You need a pass phrase to protect your RSA secret key Your pass phrase can be any sentence or phrase and may have manu words spaces punctuation or anu other printable characters 1 Enter pass phrase 0 Figure 29 PGP Key generation Window rj Enter PGP password Same Pass password for Goli IE CPGE OK Cancel Figure 30 Password for PGP RSA private key 37 SDR v 2 5 User Guide r Zcs research poda violet gmontass Mail drafts 227 Abart Saveklluit PGP Hore Text Help Sign Send Pap Action encryptsign rfc822 off originator Goli Montasser KohsariXgmontassfics ucl ac uk recipients Goli Montasser_Kohsari lt gmontassl cs ucl ac uk gt Edmund lt ucacewh cs ucl ac uk gt Edmund lt ucacewh cs ucl ac uk gt t
55. o video text and or whiteboard to be used in the session Listed alongside the name of each media will be its format SDR v 2 5 User Guide the protocol used the address and port that the media will be started up on and any other options specific to the individual medium e lf the session uses more than one type of media the name of each of the media will appear on a button Clicking the button will start up the tool for that medium only This is useful if you accidentally close down one of the tools during a session and need to start up that tool again If there is only one medium in the session the name will not appear on a button and you must click the Join button in order to start up the tool If you chose the normal interface for viewing sessions these details will initially be hidden but can be viewed by clicking the Media Details button which will appear instead e The Join button starts up all the tools for the media used in the session e The Invite button expands the Session Information Window to contain a box for inviting other SDR users to join the session See Figure 6 You can invite users even though they are using previous version of SDR In order to invite other SDR users you must know their username and the name of the computer which they are currently using So in order to invite John Smith with username johnsmith on his computer called myhost example ac uk you must type in johnsmith myhost exampl
56. onverting analogue audio and video from microphone and camera respectively to digital signals to be sent over the network and converting the digital signals back to analogue signals at the receiver s end for the audio to be played out through speakers and the video images displayed on the screen DES Data Encryption Standard DVI Audio encoding standard Framegrabber A device which captures video one frame at a time from an analogue video source Frames per second fps The frame rate for video image transmission measured in frames per second fps The higher the frame rate the better the motion rendition of the video image 30 fps is the standard necessary for full motion video To date most communication channels are not capable of transmitting large numbers of video streams concurrently With compression and the use of other signal processing algorithms a video conferencing RAT between 2 10 kilobits per second Kbps is perfectly acceptable Gamma correction AFAIK gamma correction is the correction of intensity values of cameras and monitors In the context of displays the luminescence of phosphor pixel is a 41 SDR v 2 5 User Guide GSM H 261 non linear function of the intensity of the electrons bombarding it Conversely both film and CCD cells have non linear photon intensity versus recorded intensity functions Gamma correction is a non linear correcting function to overcome these problems The number in V
57. ormation It gives the name of the person who signed the session and the date when the signature was created in the case of PGP In the case of X 509 the Distinguished Name of the user and the certificate issuer who signed the session is shown The Encryption Information button expands the Session Information Window to include a box giving you the name of the user for whom decryption was successfully done The More Information button is a link to a web page Depending on the preferences you have set clicking this button will either start up a web browser or use a web browser already running for displaying the web page The button will only be there if the person who created the session has provided a link to a webpage The Preferences Web Window allows you to choose which web browser to use for viewing the web page You have a choice of Netscape Mosaic or SDR s own built in browser Alternatively you can paste the URL into a web browser of your own choice The Contact Details button expands the Session Information Window to include a box giving you the name telephone number and email address of the person who created the session if supplied see Figure 6 It also tells you which application or version of SDR was used for creating the session announcement Under the Contact Details button a box giving you more information about the media used in the session is shown see Figure 6 There will be a line in the box for each tool audi
58. ou must know their username and the name of the computer which they are currently using So in order to invite John Smith with username johnsmith on his computer called myhost example ac uk you must type in johnsmith myhost example ac uk Note that this is not the email address of John Smith but his username followed by the address of the computer he is currently working on There is an address book to which you can add people that you often invite Press Browse to browse existing entries in the address book and to add new entries When you invite another SDR user a window will pop up on their screen telling them that you have invited them for this particular session it will provide the information in the Session Information Window and ask them to accept or reject the invitation Subsequently you will get a window popping up on your screen saying whether your guest has accepted or declined your invitation You can invite as many people as you like to take part in a quick call As soon as someone accepts an invitation the quick call will be announced on both their and your own Main SDR Window under Private Sessions see Figure 11 23 SDR v 2 5 User Guide sdrucacixe pygmalion cs uct ac uk a if Create Session Daily Listings Preferences Help Quit Public Sessions Berkeley Multimedia and Graphics Seminar BGMP MASC Canadian Radio CDT Ellemtel private CERN ATLAS UK relay cult Diesel
59. r MPSE and the Smart Card have the same password Then the Smart Card is used to encrypt your Secret Key ring this is done manually as secude pkcs enc ENVELOPED DATA p smartcard i SSDRHOME pgp secring pgp o SSDRHOME pgp secring enc 50 SDR v 2 5 User Guide rm f SSDRHOME pgp secring pgp or Click on Yes when Quitting from SDR The above will use Public Key of Smart Card to encrypt your pgp secret key ring The result will be a secring enc in your SDR PGP home directory If the file secring enc exists in your SDRHOME PGP when SDR needs to use PGP for authentication or checking the encrypted session the window Figure Appendix1 1 will appear This is for you to check if Smart card is placed in the drive Clicking OK will cause the window in Figure Appendix1 2 to appear which requires SDR to be configured with your Smart Card Location and PIN n SMARTCARD Place your smartcard Figure Appendix1 1 Checking the Smart Card Window Please configure sdr with your SMART CARD PSE name and Pin Passphrase Figure Appendix1 2 Smart Card Configuration Window 51 SDR v 2 5 User Guide Appendix 2 Configuration and Software to use with SDR 2 1 The PGP System PGP can be obtained from http www ifi uio no PGP or http www pgpi com download Most of these instructions are obtained from the official PGP documentation For full details on how to install PGP see the separate PGP Installation Guide
60. re are two audio tools which are normally used for multicasting audio on the Internet RAT and VAT When you join a session which makes use of audio you will get a small window asking you if you want to use RAT or VAT You can make either RAT or VAT your default audio tool by deselecting VAT or RAT respectively You can deselect a tool by clicking on all the boxes containing the word RAT or VAT in the SDR Preferences Window Tools Figure 14 The video tool NV has been disabled in the same way in Figure 14 Help mode 9 Balloon Help Sessions Interface Tools Web You Security The following media formats have more than one tool available to decode them Media Proto Format Available Tools audio RTP pa e ra audio RIP RTP RTP rtp rtp rtp rtp rtp rtp rtp rtp Click on the tool name to enable or disable it for the particular protocol and format if vou don t wish to be prompted Cancel Apply Preferences Save amp Apply Preferences Figure 14 SDR Preferences Window Tools 26 SDR v 2 5 User Guide 3 8 4 SDR Preferences Window Web Whenever a link to a web page is supplied for a session there is a More Information button in the Session Information Window You can decide which web browser to use for reading the web page by selecting the appropriate option in the SDR Preferences Window Web see Figure 15 e Select Use web browser already running if either Mosaic or Netscape is alre
61. reate a multi pse in your homedirectory Then if you receive a group4 pse with password testtest make sure to change the password testtest to have the same password as mpse in the same way as above that is passtest before adding it to mpse secude pseconv o mps M groupl pse group2 pse group3 pse group4 pse Now you can use this mpse with pin passtest in your SDR 1 2 3 Using the Secude Smart Card In Secude the PSE is available in two versions Software PSE and Smart Card PSE The Smart Card PSE contains the owner s secret key that is protected by a PIN the issuer public key and the serial number You can use the Smart Card with SDR in two different ways as follow 1 2 3 1 Using Smart Card with X509 At present the SDR Implementation uses Smart Card as another PSE If you would like to use smart card to authenticate or decrypt then you should configure your SDR with the Location of your Smart Card and PIN in Figure 34 Then your secret key on your smart card is used to authenticate the session On receiving any encrypted message encrypted with your public key the secret key on your Smart Card is used to decrypt the message Unfortunately Secude would not allow you to add the Smart Card PSE to your MPSE So you can either use Smart Card PSE Software PSE or MPSE Note1 X509STATE must be set to be able to use X509 and Smart Card 1 2 3 2 Using Smart Card with PGP If you are using PGP and X509 then make sure that your Software PSE o
62. ryptographically strong one way hash function of the message It is somewhat analogous to a checksum or CRC error checking code in that it compactly represents the message and is used to detect changes in the message Unlike a CRC however it is computationally infeasible for an attacker to devise a substitute message that would produce an identical message digest The message digest is encrypted by the private key to form a signature Documents are signed by prefixing them with signature certificates which contain the key ID of the key that was used to sign it a private key signed message digest of the document and a timestamp of when the signature was made The receiver uses the key ID to look up the sender s public key to check the signature The receiver s software automatically looks up the sender s public key and user ID in the receiver s public key ring The key ID of the public key used to encrypt them prefixes encrypted files The receiver uses this key ID message prefix to look up the private key needed to decrypt the message The receiver s software automatically looks up the necessary private decryption key in the receiver s private key ring 1 2 1 1 Changing PGP password The window in Figure 22 will appear every time to receive an encrypted session encrypted using PGP Typing the password will save it for duration of sdr But you can choose to have the same password for all your PGP group secret key In this case when the w
63. s will appear upside down in the whiteboard and the Upside down Landscape mode is needed in order to see the images the right way round The whiteboard normally starts up in receive only mode In order to have it start up in a mode where you can write as well you need to select the Send Receive Mode Text There are no options for text For each medium you can select the format not all the tools have format which can be set Audio The formats available are PCM DVI GSM LPC and Redundancy If all participants in the session are using the audio tool RAT as opposed to the audio tool VAT you should select Redundancy If some of the participants are using the audio tool VAT you should select DVI Video The formats for video are H 261 nv M JPEG and Cell B SDR will automatically allocate addresses and port numbers to the media 6 Click next on Figure 7e Figure 7f will appear r Sdr Create New Session Step 5 Provide Contact Details You need to provide contact details for the session so that people can get in touch if there is a problem Person to contact about this session 3 Goli Montasser Kohsari gmontass Qcs t a Goli Montasser Kohsari 0171 3807215 lt lt Back Next gt gt Accept Cancel Figure 7f 17 SDR v 2 5 User Guide You need to provide contact detail for the session 7 Click on next On Figure 7f Figure 7g will appear r Sdr Create New Session
64. such as DES PGP and X 509 Figure 1 shows two authenticated sessions in the public sessions which are signed using PGP and X509 technologies respectively In the private sessions of Figure 1 four sessions are shown which are encrypted with DES X509 and PGP and authenticated with PGP and X509 SDR can generate and send keys required for authentication and encryption Eventually it will also be possible to use Smart Card technology to authenticate a session announcement or access encrypted information in a secured repository 2 Getting started Starting up SDR on a Unix machine To start up SDR type Prompt gt SDR Starting up SDR on Windows95 NT4 0 PC Press the Start button select run This will open a small window In the Open field of this window type sar then press the OK button This will bring up the Main SDR Window SDR allows you to customise the interface The default interface will give you short labels on all the buttons allowing the interface to take up very little space on the screen However when learning how to use SDR seeing the long labels is more helpful This guide however is based on the interface showing short labels and Technical interface In order to change the interface to show the technical interface click on the Prefs button at the top of the Main SDR Window This will open the SDR Preferences Window see Figure 12 Select the tab labelled Interface and SDR v 2 5 User G
65. the Security tab and the window Figure 17 will appear Click on Add encryption group button and the window in Figure 18 will appear Fill in the information with your received group name and Encryption key and then 38 SDR v 2 5 User Guide Click OK The key is added to your SDR and can be used for encrypting and decrypting DES sessions PGP In this case the text body part of your E mail contains the password to be used with the secret key the public key and the secret key Edit the text part and save the publickey and secretkey in two different files From Begin to End To add the key files content to your public or secret key ring pgp ka keyfile keyring Now this key can be used for authentication and encryption when using PGP If you are using the same password for all your sdr session group keys then change the RSA password to be the same for all your received secret key This is done with pgp ke userid This is described in Appendix 1 X509 In this case where the text part of your E mail contains the password To be used for RSA secret key and uuencoded PSE file Edit the file and save the UUencoded part of the body in a file Use uudecode to get the PSE You can add this to your MPSE as described in Appendix 1 or use it on its own to decrypt and authenticate a session 3 8 6 7 Ending SDR You can end your SDR by clicking on the Quit button in the top right hand corner of the main SDR window of Figure 20 If X
66. uide you will get the window in Figure 13 You may need to make the following changes In the View Session box select Technical Interface In the Label Detail box select Short labels expert mode Then click the Save amp Apply Preferences button in the bottom right hand corner of the window Quick guide to using SDR SDR is like an online TV listings guide SDR lists all the sessions including authenticated and encrypted sessions after checking the signature and decrypting the sessions that are currently scheduled to happen on the Mbone SDR will also let you join the sessions i e automatically start up the relevant tools on the correct addresses ports by the click of a button SDR lets you announce your own secure sessions SDR can be used to generate symmetric and asymmetric keys Smart Cards can be used to encrypt personal information to be used for authentication and encryption SDR allows you to make quick calls or multimedia phone calls to other SDR users A quick call is really the same as any other session except that only people you invite to your quick call will be notified of the call session The Main SDR Window see Figure 1 contains a list of sessions which are either on or have been announced to take place sometime in the future An icon telling you which type of session it is precedes each session Ga P Is a broadcast i e the session is not interactive New users may join the session
67. upon in advance either through email or phone or assigned using SDR Protocol QCIF PGP RAT A set of standards that govern the transfer of information between computers over a network or via telecommunications systems To reduce errors the computers at both ends of a communications link must follow the same protocol Quarter Common Image Format with dimensions of 176x144 pixels Pretty Good Privacy Robust Audio Tool Receive only A condition where a tool is used to receive information but cannot transmit Redundant audio encoding RSA RTP A technique to protect against packet loss where a second low bandwidth version of the original encoding is piggy backed onto the preceding packet so that when single packets are lost the redundant version is played back instead of silence A popular public key encryption algorithm developed by MIT professor Ron Rivest Adi Shamir and len Adelman 44 SDR v 2 5 User Guide Real Time Protocol is an application level protocol that provides real time support for multimedia communication SCIF Super Common Image Format with dimensions of 704x576 pixels SDR Multicast Session Directory tool Silence suppression Silence suppression is used in packet voice systems to reduce the output bandwidth of an audio system by exploiting the on off nature of speech 50 savings are possible TTL TTL stands for time to live and determines how far multicast packages can travel ov
68. y ring is encrypted using the Smart Card then the user needs to give the Smart Card information to be able to authenticate a session or decrypt a session This implementation is done because at present the repository information is not available The whole procedure is defined in Appendix 1 Section 1 2 2 2 Seeing what sessions are on The list of sessions in the Main Window is an alphabetical list of all sessions which have been announced to take place thus a session may be on at the moment or may have been scheduled to take place some time in the future In order to see what sessions are on click on the Daily Listings button at the top of the Main Window The Daily Listings Window shows sessions on a daily basis like a TV or radio guide The Daily Listings Window uses a calendar format see Figure 2 Dates marked with a blue box are days on which sessions have been scheduled to take place Click on the date that you are interested in and the window will expand to include a window showing the sessions for that particular day see Figure 3 Moving the mouse over the time line or the name of the session will cause it to go red Clicking on a session which is showing red will open a Session Information Window see Figure 4 giving you more information about that session Due to a software bug not all sessions are displayed in the Daily Listings Windows i e there may be sessions which have been announced but are not displayed in the D

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