TANDBERG D12817-05 - Manual (Page 77)

TANDBERG Videoconferencing System
77
Appendices
Encryption
All TANDBERG systems support both AES* and DES encryption. By default this feature is enabled such that
when connecting with any other video system or MCU, a TANDBERG system will attempt to establish a secure
conference using AES* or DES encryption. The TANDBERG system will attempt this for both IP and ISDN
connections. Where a remote system or MCU supports encryption, the highest common encryption algorithm will
be selected on a port by port basis.
The type and status of the encryption negotiated is indicated by padlock symbols and on-screen messages.
Encryption on the TANDBERG systems is fully automatic, and provides clear security status indicators;
An open padlock indicates that encryption is being initialized, but the conference is not yet encrypted.
Single padlock indicates DES encryption.
Double padlock indicates AES encryption.
In addition to on-screen indicators the ‘Call Status’ menu provides two information fields regarding call encryption.
The first field is the ‘Encryption Code’ which will identify either ‘AES’ or ’DES’. The second field is the ‘Encryption
Check Code’ and is comprised of an alphanumeric string. This string will be the same for systems on either side
of an encrypted conference. If the Check Codes do not match this would indicate that the call has been exposed
to a ‘Man In The Middle’ attack.
When a TANDBERG codec with MultiSite functionality hosts a conference, the highest possible encryption
algorithm will be negotiated on a site by site basis. MultiSite conferences can therefore support a mix of AES
and DES encrypted endpoints in the same conference.
A conference will only be as secure as its ‘weakest link’. Even though conference participants may have
negotiated and be running AES encryption, if just one participant has negotiated DES encryption, the AES
system will display the single padlock symbol to advise all users of the lowest encryption mechanism currently in
effect.
All TANDBERG endpoint supporting DES encryption can upgrade to AES encryption by applying TANDBERG’s
AES Encryption option. Please contact your TANDBERG representative for more information.
The standards supporting the encryption mechanisms employed by TANDBERG are: AES*, DES, H.233, H234
and H.235 with extended Diffie Hellman key distribution via H.320, H.323 and Leased Line connections.
* - Optional feature