Unruh <unruh-spam@physics.ubc.cawrites:
No idea what this means. DES was replaced as teh standard by
AES. DES is still used all over the place (Eg, I think
ATMs). Unix-variant password hashing has changed over to an MD5
derived hash (No it is not MD5 anymore than crypt(3) is DES)

an issue was that brute-force attack on DES key was shown to be doable
on the order of a day with some custom hardware.

there is use of 3des which involves three steps involving two
keys (which gives you 112bit instead of 56bit as resistance to brute
force attacks, each additional bit effectively doubles the attack
effort).

one of the uses of single DES key has been DUKPT for transactions
which have a lifetime of possible a couple seconds (i.e. derived
unique key per transaction). an attack on a DUKPT key with a lifetime
of a couple seconds needs to be done within the window of the
transaction lifetime (aka it isn't so much for confidentiality but
integrity).

some of it is still cost/benefit ratio for the attacker does the
possible benefit from the attack justify the effort put into the
attack (stituations possibly yielding couple million benefit is easier
to justify an attack compared to attack that might only yield a couple
hundred).

misc. past posts mentioning dukpt
http://www.garlic.com/~lynn/aadsm3.htm#cstech8 cardtech/securetech & CA PKI
http://www.garlic.com/~lynn/2003g.html#9 Determining Key Exchange Frequency?
http://www.garlic.com/~lynn/2003g.html#42 What is the best strongest encryption
http://www.garlic.com/~lynn/2003o.html#46 What 'NSA'?
http://www.garlic.com/~lynn/2004c.html#56 Bushwah and shrubbery
http://www.garlic.com/~lynn/2004f.html#9 racf
http://www.garlic.com/~lynn/2005k.html#23 More on garbage
http://www.garlic.com/~lynn/2005l.html#8 derive key from password
http://www.garlic.com/~lynn/aadsm18.htm#53 ATM machine security
http://www.garlic.com/~lynn/aadsm19.htm#36 expanding a password into many keys