[ACTION-120] Review SP 800-57 for HMAC-SHA256 (Issue 74)

I think issue 74 refers to a question about whether it is necessary to require HMAC-SHA256 in 1.1.

According to NIST Special Publication 57 Part 1 (http://csrc.nist.gov/publications/nistpubs/800-57/sp800-57-Part1-revised2_Mar08-2007.pdf), HMAC-SHA1 is acceptable at the equivalent of 128 bits of security even though SHA256 is required for signature applications (see table 3 on page 64). Hence, I don't believe it is necessary to require HMAC-SHA256 in 1.1.

Kelvin