On Wed, Aug 26, 2015 at 7:04 AM, Kostas Savvidis <ksavvidis@xxxxxxxxx> wrote: > The online documentation contains the attached passage as part of the "C-Extensions” chapter. There are no actual machines which have an " integer mode wide enough to hold 128 bits” as the document puts it. This would be a harmless confusion if it didn’t go on to say “… long long integer less than 128 bits wide” (???!!!) Whereas in reality "long long int” is 64 bits everywhere i have seen. > On 64-bit platforms, a 128-bit integer is available. I don't know how widespread it is, but its available on the Intel Mac I use and some of my P4 machines. When using OpenSSL, if you configure with enable-ec_nistp_64_gcc_128, then Elliptic Curve Diffie-Hellman is about 2x to 4x faster. You have to enable enable-ec_nistp_64_gcc_128 manually because OpenSSL's configure cannot detect it. See, for example https://wiki.openssl.org/index.php/Compilation_and_Installation. Jeff
