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FYI: RFC 2144 on CAST.

1997-06-27 12:11:38
The informational RFC on CAST has been published, and is available from
http://ds.internic.net/rfc/rfc2144.txt and
ftp://ds.internic.net/rfc/rfc2144.txt.

From section 3, "Intellectual Property Considerations":  "The CAST-128
cipher described in this document is available worldwide on a
royalty-free basis for commercial and non-commercial uses.".

For ease of implementation, note also section 2.5, "Variable Keysize":

The CAST-128 encryption algorithm has been designed to allow a key size
that can vary from 40 bits to 128 bits, in 8-bit increments (that is,
the allowable key sizes are 40, 48, 56, 64, ..., 112, 120, and 128
bits).

Note that although CAST-128 can support all 12 key sizes listed above,
40 bits, 64 bits, 80 bits, and 128 bits are the sizes that find utility
in typical environments.  Therefore, it will likely be sufficient for
most implementations to support some subset of only these four sizes.

pww



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