SHA-based encryption function in Python

[Richard Parker]

Paul Crowley wrote on 4/25/02 12:42 AM:

> Not so - it is far easier for the attacker to do 2^64 offline work
> than it is to present 2^64 forged messages to the remote end.

Paul Rubin's application is general purpose library.  It is entirely
plausible that Paul Rubin's library could be used in an application that
essentially provides the attacker with an oracle.  I agree that it is not a
good idea to replace an operation that to break requires 2^64 queries for
one that requires 2^64 work.  However, while queries are, in practice,
usually more difficult, I think it is a mistake in a general purpose library
to assume that making 2^64 queries is necessarily any "harder" than 2^64
work.

-Richard