Hi, for the DRBG and the LRNG work I am doing, I also test the speed of the DRBG. The DRBG can be considered as a form of block chaining mode on top of a raw cipher. What I am wondering is that when encrypting 256 16 byte blocks, I get a speed of about 170 MB/s with the AES-NI driver. When using the aes-generic or aes- asm, I get up to 180 MB/s with all else being equal. Note, that figure includes a copy_to_user of the generated data. To be precise, the code does the following steps: 1. setkey 2. AES encrypt 256 blocks and copy_to_user 3. Use AES to generate a new key and start at step 1. I am wondering why the AES-NI driver is slower than the C/ASM implementations given that all else is equal. Note, if I have less blocks in step 2 above, AES-NI is becoming faster. E.g. if I have 8 blocks or just one block in step 2 above, AES-NI is faster by 10 or 20%. Ciao Stephan -- atsec information security GmbH, Steinstraße 70, 81667 München, Germany P: +49 89 442 49 830 - F: +49 89 442 49 831 M: +49 172 216 55 78 - HRB: 129439 (Amtsgericht München) US: +1 949 545 4096 GF: Salvatore la Pietra, Staffan Persson atsec it security news blog - atsec-information-security.blogspot.com -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
