> On Mon, Dec 29, 2014 at 8:18 AM, Florian Weimer <f...@deneb.enyo.de> wrote: >> To check an OpenPGP fingerprint for correctness, it is sufficient (for >> practical purposes) to compare the leading and trailing eight >> hexadecimal digits, and perhaps a few digits in the middle. > > It is, only if you prefer these odds... > 16^16/2^64 = 1.00 > 16^19/2^76 = 1.00
Huh? > I believe collisions in the former are already well known. Producing a colliding pair isn't *that* hard (it's been done for the key ID part in V4 keys), but computing a partial 64-bit collision for a specific key is still expected to be quite expensive. (The chosen-prefix collisions for MD5 should completely break V3 certification signatures, but I don't think anything has been published yet.) _______________________________________________ cryptography mailing list cryptography@randombit.net http://lists.randombit.net/mailman/listinfo/cryptography
