DES

[Matthew J Ghio]

Jamie Jamison <jamie at 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.