17 Dec
2003
17 Dec
'03
11:17 p.m.
Tim May had it exactly right in his post entitled "Silver Linings and Monkey Wrenches" (thanks Tim). The only thing I can add is that forcing them to attack a 40 bit key is better than giving them the whole key thru some LEAF scheme ala Clipper.
Your point may be valid, but who is attacking a 40 bit key? Is cracking 40 out of 64 bits of a 64-bit RC4 key as hard as cracking a 40 bit key, or does knowing a significant portion of the key make the search considerably easier than brute force? I've never heard anyone make an assertion either way, except that some people seem to assume a the difficulties are the same. Thanks, David