# GMP versus TFM on an AMD64

*From*: tomstdenis@xxxxxxxxx*Date*: 17 Mar 2006 21:30:17 -0800

For all those who were trying to insult me about how much GMP was

faster...

:-) ^_^ grin ^_^

This is on an Opteron 275 running the latest GMP and my newly crafted

GMP plugin for LTC (basically calls mpz_powm).

GMP:

RSA-1024 encrypt_key took 121194 cycles

RSA-1024 decrypt_key took 1845297 cycles

RSA-1280 encrypt_key took 169824 cycles

RSA-1280 decrypt_key took 3278677 cycles

RSA-1536 encrypt_key took 229255 cycles

RSA-1536 decrypt_key took 5317780 cycles

RSA-1792 encrypt_key took 301444 cycles

RSA-1792 decrypt_key took 8069089 cycles

RSA-2048 encrypt_key took 384635 cycles

RSA-2048 decrypt_key took 11513466 cycles

Compare to TFM:

RSA-1024 encrypt_key took 178994 cycles

RSA-1024 decrypt_key took 1376474 cycles

RSA-1280 encrypt_key took 285829 cycles

RSA-1280 decrypt_key took 2228425 cycles

RSA-1536 encrypt_key took 337265 cycles

RSA-1536 decrypt_key took 3488658 cycles

RSA-1792 encrypt_key took 398694 cycles

RSA-1792 decrypt_key took 5109385 cycles

RSA-2048 encrypt_key took 464253 cycles

RSA-2048 decrypt_key took 6981056 cycles

For the smaller sizes GMP does better mostly because I setup more k-ary

table than I should. But on the decrypt side TFM clearly wins.

I don't have ECC timings yet [I have ECC working though] as GMP seems

to lack a publicly exported reduction function. I'll craft one doing

whole number montgomery reduction. Right now I'm using mpz_mod and it

makes it between 2x and 3x slower than TFM. I won't list them since I

acknowledge that isn't a fair fight.

Roughly speaking both shared objects [for GMP and TFM] are about the

same size. Though GMP does some odder things TFM doesn't. That said

for crypto purposes I don't see the draw for GMP. It's clearly not

faster than TFM, at least on my AMD64 box.

Tom

.

**Follow-Ups**:**Re: GMP versus TFM on an AMD64***From:*Felix Rawlings

**Re: GMP versus TFM on an AMD64***From:*D. J. Bernstein

**Re: GMP versus TFM on an AMD64***From:*Felix Rawlings

**Re: GMP versus TFM on an AMD64***From:*tomstdenis

**Re: GMP versus TFM on an AMD64***From:*tomstdenis

**Re: GMP versus TFM on an AMD64***From:*D. J. Bernstein

**Re: GMP versus TFM on an AMD64***From:*tomstdenis

**Re: GMP versus TFM on an AMD64***From:*Felix Rawlings

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