Re: [kernel-hardening] Re: HalfSipHash Acceptable Usage
From: Rik van Riel <hidden>
Date: 2016-12-21 16:46:12
Also in:
linux-crypto, lkml
On Wed, 2016-12-21 at 10:55 -0500, George Spelvin wrote:
Actually, DJB just made a very relevant suggestion. As I've mentioned, the 32-bit performance problems are an x86- specific problem. ARM does very well, and other processors aren't bad at all. SipHash fits very nicely (and runs very fast) in the MMX registers. They're 64 bits, and there are 8 of them, so the integer registers can be reserved for pointers and loop counters and all that. And there's reference code available. How much does kernel_fpu_begin()/kernel_fpu_end() cost?
Those can be very expensive. Almost certainly not worth it for small amounts of data. -- All Rights Reversed.
Attachments
- signature.asc [application/pgp-signature] 473 bytes