From rjh at sixdemonbag.org Fri May 1 03:04:54 2026 From: rjh at sixdemonbag.org (Robert J. Hansen) Date: Thu, 30 Apr 2026 21:04:54 -0400 Subject: quantum computing and symmetric algotithms In-Reply-To: References: Message-ID: <2ff66836-8d9a-4336-b52d-5c4d23b298fe@sixdemonbag.org> > It would be useful in discussions on quantum computing and > cryptography not to miss that vulnerability (if and to the extent it > exists) only pertains to the asymmetric algorithms. As far as we > know, no modern symmetric block cipher is affected. True, with 3DES as a possible exception. There's a meet in the middle attack that means with truly ludicrous amounts of hardware it could be reduced to complexity 2**112, which is ... not practical for Grover's algorithm for many reasons, but is definitely not as wildly impractical as I'd like. -------------- next part -------------- A non-text attachment was scrubbed... Name: OpenPGP_signature.asc Type: application/pgp-signature Size: 236 bytes Desc: OpenPGP digital signature URL: