Re: Just how does it know?

noggle@isoc.net
Thu, 01 May 1997 19:21:33 GMT


On Thu, 1 May 1997 07:48:35 -0500 (EST), you wrote:

>From http://www.rsa.com/rsalabs/97challenge/index.html:
> For each contest, the unknown plaintext message is preceded by
> three known blocks of text that contain the 24-character phrase
> "The unknown message is: ".
>If a key encrypts the first 24 characters correctly, I imagine it will be
>the right key.

Well considering that DES is a 64 bit cypher, I hope it doesn't check the first
24 characters, but the first 8 to see if they en/decrypt correctly (I don't know
if he's going from plaintext to cyphertext or the other way around), and then
checking the rest if it ends up being the same. If he checked the first 24
characters all the time then it would waste time in multiple en/decryptions.

Jason Gmoser
noggle@isoc.net