Version 4 of sha2

Updated 2005-02-22 13:25:37

The sha1 secure hash algorithm produces a digest of 160 bits. This provides 80 bits of security against collisions given the birthday attack (ref). An update document from NIST [L1 ] specifies a new family of secure hashing algorithms with longer digest lengths, specifically SHA-256, SHA-384, and SHA-512. An additional update also specifies SHA-224 [L2 ].

tcllib now includes a pure-tcl implementation of SHA-224 and SHA-256. For comparison, here are some timing data for the pure-Tcl implementation of all the digests in tcllib

   1 md4    time:  190 microseconds per iteration
   1 md5    time:  236 microseconds per iteration
   1 rmd128 time:  337 microseconds per iteration
   1 rmd160 time:  525 microseconds per iteration
   1 sha1   time:  826 microseconds per iteration
   1 sha224 time: 1117 microseconds per iteration
   1 sha256 time: 1126 microseconds per iteration

See also sha1, md4, md5, ripemd, cryptkit

[ Category Package, subset Tcllib | Category Cryptography ]