From: (Ken Pizzini)
Newsgroups: sci.crypt

Subject: Re: Algorithms
Date: 12 Nov 1994 20:39:58 GMT
Organization: What, me?
Lines: 13
Message-ID: <3a396u$>
References: <>

In article <>,
Terry Ritter  wrote:
> We commonly assume that the keysize of Triple DES is at least twice
> as long (has 2**56 times as many keys) as ordinary DES, and that may
> be.  But consider the simple newspaper amusement ciphers, which are
> also Simple Substitution:  Clearly, even three sequential cipherings
> through different alphabet permutations will be no harder to solve
> than one.  (In this case we do not solve for each of the keys
> independently, but this probably does not matter.)

Monoalphabetic substition ciphers form a group.  DES does not.

                --Ken Pizzini