http://www.gcn.com/online/vol1_no1/44453-1.html
By William Jackson
GCN Staff
06/13/07
The National Institute of Standards and Technology has revised two
Federal Information Processing Standards specifying algorithms for
cryptographic hashing. Drafts of FIPS 180-3 [1] and FIPS 198-1 [2] have
been released for three months of public comment.
FIPS 180-3 replaces Publication 180-2 and specifies five secure hash
algorithms (SHAs). The algorithms, when combined with a message, produce
a message digest that should be unique to the original message. These
can be used for digital signatures and message authentication codes. In
the new draft, SHA-1, SHA-224 and SHA-256 are used to produce digests of
shorter messages, while SHA-384 and SHA-512 can be used for longer
messages. They produce digests ranging in length from 160 to 512 bits,
depending on the algorithm used.
The algorithms are called secure because it is unlikely that the
original message could be derived from the digest produce by the
algorithm, or that the algorithm could produce the same digest for more
than one message. This gives a high probability that each digest is
unique to its message and that the digest can be used to accurately
verify a digital signature or a message authentication code.
FIPS 198-1 replaces Publication 198 and specifies an algorithm for
applications requiring message authentication. Using a secret key that
is shared with the intended recipient of a message, the sender produces
a code or message digest unique to the message being sent. The recipient
uses the same key to produce a code of the message being received. If
the codes match, the recipient can be sure that the message has not been
altered and that it came from the other holder of the key.
Comments are being accepted on both proposed standards until Sept. 10.
Comments should be sent either to proposed180-3 (at) nist.gov or to
proposed198-1 (at) nist.gov, with a subject line that reads Comments on
draft 180-3 or Comments on draft 198-1.
[1] http://csrc.nist.gov/publications/drafts/fips_180-3/draft_fips-180-3_June-08-2007.pdf
[2] http://csrc.nist.gov/publications/drafts/fips_198-1/draft_FIPS-198-1_June-08-2007.pdf
Received on Thu Jun 14 00:09:30 2007