Multiple symetric cyphers

[Eric Hughes]

   From: paul at poboy.b17c.ingr.com (Paul Robichaux)

   Must I
   require the user to tell that program what cypher was used to encrypt
   the file she wishes to decrypt?

Only if you don't want to store the type alongside.  See below.

   Is storing the cypher type as part of the encrypted file a weakness?

Well, it's no weaker than current systems.  PGP stores the cipher type
in the source code: it's always IDEA.  One should allow, however, the
cipher type to be empty alongside the data so that another tool can
store cipher information.

Eric