On Wednesday, October 5, 2011, Robert J. Hansen wrote: > On 10/5/11 10:02 AM, Aaron Toponce wrote: > > Does GnuPG support symmetric multiprocessing? If so, my Google-fu is > > failing me, as is reading the available documentation. Reason I ask is > > because encrypting 1TB files is fairly CPU intensive, and it appears that > > it's only using 1 of my 4 cores. > > Short version: wouldn't do you any good even if it did. > > Long version: CTAK encryption isn't parallelizable: encrypting block N > successfully depends on successfully encrypting block N-1, which in turn > depends on successfully encrypting block N-3, and so on. There's no way > to partition it into independent subproblems. A clever hack lets you > parallelize decryption, but even then it's probably not worth it -- the > amount of time spent doing disk I/O will be multiple orders of magnitude > larger than the amount of time decrypting. > Certain modes of AES can be safely parallelizable in both directions: CTR can be since it uses a counter value to make each encryption different for the XOR operation used. ESSIV or XTS are also useful in parallelization, but might need tweaking for single-file encryption.
-- Thomas Harning Jr.
_______________________________________________ Gnupg-users mailing list [email protected] http://lists.gnupg.org/mailman/listinfo/gnupg-users
