[Cryptography] Exotic Operations in Primitive Construction

[Peter Gutmann]

Phillip Hallam-Baker <phill at hallambaker.com> writes:

>The reason we get rotate is that it is cheap: It is in essence a combination
>of a Left shift and a right shift.

If you're referring to an implementation in C, it's not even that any more,
any compiler from the last 15-20 years has a rotate recogniser and will
translate 'x << y | x >> ( wordsize - y )' into a single rotate instruction.

Peter.