Re: Generate a one-time pad from say a 256bit key?

"Tom St Denis" <tomstdenis@xxxxxxxxx> writes:
Serpent is a decent choice, not nearly as fast as Rijndael.

Serpent might faster than AES-128 if you use a bit-slice
implementation with x86 XMM instructions. I don't know if anyone has
tried that yet. Probably not worthwhile. Some of the Ecrypt stream
cipher candidates are way faster than AES and look promising in terms
of security. Block ciphers have a property (i.e., invertibility)
which is not necessary for many uses of crypto, and which appears to
be somewhat expensive. We're in the habit of using them because
history starting with DES, but it's sort of as if public-key crypto
had been invented earlier than secret-key, and we got in the habit of
using RSA even for symmetric encryption, despite its slow speed. But
we should be looking to switch to stream ciphers, now that we have a
better understanding of what we want our primitives to do.
.