Date: Mon, 16 Oct 1995 13:51:27 -0700 From: Hal <hfinney@shell.portal.com> Subject: Human ID through insecure channel

Here is an example of the Matsumoto/Imai scheme for identifying yourself via a shared secret over an insecure channel, a system which is simple enough to be done in your head but which can withstand repeated observations by an adversary without being broken.

Hal, has this been written up someplace where I might read their description? From your description of it, I have a way to break it in O(N) samples, where N is the number of characters in the challenge string and the factor of proportionality is strictly a function of how sure you want to be that you have a correct break. - Carl +--------------------------------------------------------------------------+ |Carl M. Ellison cme@tis.com http://www.clark.net/pub/cme | |Trusted Information Systems, Inc. http://www.tis.com/ | |3060 Washington Road PGP 2.6.2: 61E2DE7FCB9D7984E9C8048BA63221A2| |Glenwood MD 21738 Tel:(301)854-6889 FAX:(301)854-5363 | +--------------------------------------------------------------------------+