Re: DES

Jamie Jamison <jamie@apl.washington.edu> wrote:

Two questions about DES.

1) If the current, 56 bit, DES system is so easy to break why don't people switch over to a DES system that uses a larger key space, say 128 bits? People obviously aren't, so what's the barrier to this?

It's not easy to break. It is possible to break it with about $1 million worth of specialized computing hardware. Many programs, such as PGP, do use larger keys.

2) How much longer would it take to break triple DES versus standard DES using one of the key-breaking machines described?

If all combinations had to be tried, it would take 2^112 times longer to break a triple DES (168 bit) code than to break the standard 56 bit code.