Re: Phil Zimmerman on 'The Death of DES'

I personally favor triple DES + IDEA. The notion is that if triple DES is weak maybe IDEA isn't, and vice versa -- you are no weaker than the strongest of the two systems. Perry Carl Ellison says:

Single DES is weak, for a known plaintext attack. I think we knew that. We didn't know how weak.

We can extrapolate to an NSA machine with 1 second scan of all keys, perhaps.

So --

1. use triple DES

2. before using DES, XOR with a stream from a decent PRNG (destroying the known plaintext)

3. in between DES operations, mix bytes up as with tran (posted on sci.crypt occasionally, avbl from me by mail or on ripem.msu.edu) -- spreading bytes out within a huge block, further hiding any known text

- Carl