Subject: [AVTCORE] Comments on the draft-ietf-avtcore-srtp-aes-gcm-06

From: Woo-Hwan Kim <[email-masked]>
Date: Thu, 27 Jun 2013 14:22:38 +0900

Hi.

Here are some comments on the draft-ietf-avtcore-srtp-aes-gcm-06.

1. In section 5.2, Tag_Size_Flag is used for CCM mode input and it is
written that the tag size for GCM mode is determined by the algorithm
choice.
There is no difference between CCM and GCM from the point of view that the
ciphersuite can determine the tag length.
CCM needs tag length in the input formatting function while GCM does not.
But I think it does not imply that the inputs of GCM and CCM differ and it
is better to be consistent.

2. AES-CCM ciphersuites is defined for each tag length except but Section
14.1.
I think it is better to add the following ciphersuites in Section 14.1 as
well as other parts of the draft.
- AEAD_AES_128_CCM_8
- AEAD_AES_256_CCM_8
- AEAD_AES_128_CCM_12
- AEAD_AES_256_CCM_12

3. Section 6, Section 11.1
 (2^24)-16 octets => (2^28)-16 octets

Regards, Woo-Hwan Kim