CAST key size (fwd)

Cypherpunks Maintenance Account cpunks at
Wed Aug 27 17:56:32 PDT 1997

----- Forwarded message from Peter Gutmann -----

>From cpunks  Mon Aug 25 08:03:32 1997
From: pgut001 at (Peter Gutmann)
To: hvdl at
Subject: Re:  CAST key size
Reply-To: pgut001 at
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Date: Mon, 25 Aug 1997 23:39:58 (NZST)
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>Just a quick question on the keysize of the CAST algorithm. According to
>the bible of Bruce,  CAST uses a 64 bit keysize, while  in the manual of
>PGP 5.0 (page 89), Phill states that CAST uses a 128 bit keysize...
>Am I missing something?
"CAST" isn't a particular algorithm, but a design process for creating 
algorithms.  The particular CAST instantiation used in PGP 5 is either 
CAST-128 or CAST5, depending on who you ask.  Other versions of CAST abound, 
including an earlier one used by MS for unknown purposes which had a 64-bit 
key, probably the one Bruce is referring to.

----- End of forwarded message from Peter Gutmann -----

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