Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site cbosgd.UUCP Path: utzoo!watmath!clyde!floyd!harpo!ihnp4!cbosgd!mark From: mark@cbosgd.UUCP (Mark Horton) Newsgroups: net.crypt Subject: Re: One-time pads Message-ID: <986@cbosgd.UUCP> Date: Sun, 19-Feb-84 19:15:31 EST Article-I.D.: cbosgd.986 Posted: Sun Feb 19 19:15:31 1984 Date-Received: Mon, 20-Feb-84 08:59:40 EST References: <2540@azure.UUCP> Organization: AT&T Bell Laboratories, Columbus Lines: 20 I've seen two people claim that the chances of the cleartext getting sent out unencrypted due to a long string of zeros in the key is no greater than some other message coming out due to a random key. I think these people are assuming that the random number generator used is sure to generate uniformly distributed random numbers. With a good psuedo random number generator, you can easily prove that this is the case. But with a true random number generator, based on noise from some analog source, for example, you are NOT assured that the numbers are uniform. Maybe there were excessive sunspots the day the key was generated, and the noise levels were very low, resulting in all the analog values being sampled being below the zero cutoff, and a zero random number value for each try. Or perhaps one of the components breaks, with the same result. The obvious thing to do is to have the algorithm watch the key, and if it sees a long string of zeros or ones, to refuse to send the message, but to alert an operator instead. Mark Horton