ITU Telecommunication Standardization Sector	Document  AVC-1150
Study Group 16
Former Q.2&3/15 Rapporteur Meeting	12 February 1997
Boston, 18-21 February 1997

SOURCE: 	Japan
TITLE:	Comments on Draft H.Secure
Purpose:	Discussion
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1.  Introduction
This document shows some comments on draft H.Secure (AVC-1124; 7 Feb. ‘97 version) and security issues for H.310 terminal.

2.  Comments on H.Secure draft (AVC-1124)
-	The encryption algorithms registered in NCC (National Computing Centre) in accordance with ISO9979 are appropriate for options.  However, the algorithms listed in H.245 mediaEncryptionAlgorithm messages don’t cover all of them.  At least, the NCC encryption algorithms which specifications are opened should be listed in H.245 mediaEncryptionAlgorithm messages as options.
-	ECB is the weakest mode compared with CBC, CFB and OFB (see Annex).  In some cases, ECB mode will be difficult to guarantee enough security.  To be responsible for the variety of security levels, H.Secure should allow the use of other modes (CBC, CFB and OFB) .

3.  Security issues for H.310 terminal
-	As to the Annex 6 to AVC-1099, H.310 security requirements may be different among RAST, ROT and SOT.  We have to analyze and discuss them separately.
-	It is necessary to clarify which protocol layers provide the security functions.  In order to independently provide the encryption function for each media stream, MPEG-2 Systems layer would be adequate .

References
[1] 	AVC-1124  “Security and Encryption for H Series (H.323 and other H.245 based) multimedia terminals. (Draft H.Secure)”, Jim Toga, 7 February, 1997.
[2] 	Annex 6 to AVC-1099  “Security Requirements and Scope for H.Secure”, Jim Toga, 20 December, 1996.

END

Annex