On Fri, Apr 12, 2013 at 10:43 AM, Niels Möller <[email protected]> wrote:
> Nikos Mavrogiannopoulos <[email protected]> writes: > > > It is a bit unfair to compare umac with plain hashes. > For large messages I think it is fair; the O(n) work is the same for > hash and hmac-hash; hmac only adds O(1) work of hashing some short > constant-size strings. And the benchmark program only tries to measure > the O(n) term. > That's correct if you are thinking about long messages. In practice, however, MACs are used with short messages. In TLS a MAC is used with a message that has a maximum of a 15kb, and in DTLS most messages are around the ethernet packet size (1500 bytes). At these sizes any overhead O(1) may be critical to performance. > > In the last patch > > there was an addition to the benchmarks to have HMAC performance as well. > Sorry I missed that. Was there really any measureable difference between > hash and hmac-hash? The "update" processing is the same (except perhaps > an additional function call). > I don't remember. It was a different test. I only have a copy of the mail I sent you and the numbers were the following: umac-aes-4 full 737.86 umac-aes-8 full 801.11 umac-aes-12 full 771.41 umac-aes-16 full 724.91 hmac-md5 full 481.41 hmac-sha1 full 437.43 hmac-sha256 full 171.49 hmac-sha3_256 full 200.44 On the same system now I get: md5 update 506.93 sha1 update 446.76 sha256 update 197.33 sha3_256 update 231.99 and for UMAC: umac32 update 3596.71 umac64 update 1967.24 umac96 update 1564.06 umac128 update 1304.87 regards, Nikos _______________________________________________ nettle-bugs mailing list [email protected] http://lists.lysator.liu.se/mailman/listinfo/nettle-bugs
