Subject: Re: [AVTCORE] Verifying consensus on draft-ietf-avtcore-srtp-aes-gcm-13

From: Woo-Hwan Kim <[email-masked]>
Date: Mon, 21 Jul 2014 10:59:39 +0900

Hi.
Here are some comments on the draft-ietf-avtcore-srtp-aes-gcm-13.

1. section 11.
Hence P_MAX is 2^24-1.. => Hence P_MAX is 2^24-1.

2. section 13.1.
it MAY support the four other variants shown
=>
it MAY support the two other variants shown
(GCM_8 variants are discarded)

3. section 14.2.
by the log base 2 of the of blocks of encrypted and/or authenticated data
in a packet
=>
by the log base 2 of the blocks of encrypted and/or authenticated data in a
packet

4. Table 13
Two rows for 16 bytes tag should be interchanged as follows.

128(CCM) 2^86 tries 2^96 tries 2^106 tries
116(GCM) 2^98 tries 2^ 108 tries 2^118 tries
=>
128(CCM) 2^98 tries 2^ 108 tries 2^118 tries
116(GCM) 2^86 tries 2^96 tries 2^106 tries

5. section 15.3.
This list is, of course, intended for use with CM and GCM.
=>
This list is, of course, intended for use with CCM and GCM.

SRTP encr Algorithm => SRTP Encr. Algorithm

6. section 15.3.
e.g., AEAD_AES_256_GCM_8
=>
e.g., AEAD_AES_256_GCM_12

Since GCM_8 is discarded in the draft, a ciphersuite with other tag length
may be preferred as an example.

Sincerely, Woo-Hwan Kim