|
|
|
|
|
|
|
|
|
|
|
|
| home | help | back | first | fref | pref | prev | next | nref | lref | last | post |
Date: Tue, 24 Jun 1997 22:59:10 -0700 From: Tom Weinstein <tomw@netscape.com> To: Adam Back <aba@dcs.ex.ac.uk> Cc: davidlu@sco.com, trei@process.com, cypherpunks@cyberpass.net Reply-To: Tom Weinstein <tomw@netscape.com> Adam Back wrote: > > Re comments that I should re-read the paper, here is what Wiener's > paper says about estimated costs of a specialized DES key breaker: > > $100,000 for a machine to break DES in an average of 35 hrs > $1 mil for a machine to break DES in an average of 3.5 hrs > $10 mil for a machine to break DES in an average of 21 mins > > It was as Peter says published in 1993. > > Wiener also budgets for $500,000 in design costs (wages, parts, fab > etc). > > Another interesting part of the design is that it is based on a > pipelined chip, clocked at 50Mhz which can try 50 Million keys/sec. > > 35 hours sounds a reasonable amount of time to break a Swift banking > transfer key protecting trillions of dollars of funds. One thing that I haven't heard anybody mention yet is that if time is important, you can break keys in an arbitrarily short period of time, if there's a continuous sequence of transactions. Assume it takes 35 hrs to crack a key (with 50% probability), This means that you have a 1.4% chance to crack it in one hour. If you give up after an hour and pick a new transaction to crack, you have a 50% chance of cracking at least one transaction after 48 hours, and they will all have been cracked in less than an hour. -- What is appropriate for the master is not appropriate| Tom Weinstein for the novice. You must understand Tao before | tomw@netscape.com transcending structure. -- The Tao of Programming |
|
|
|
|
|
|
|
|
|
|
|
|
| home | help | back | first | fref | pref | prev | next | nref | lref | last | post |