[Cryptography] Generating random values in a particular range

[Sidney Markowitz]

Jerry Leichter wrote on 6/08/16 7:39 AM:
> Guess what:  The use of that second technique *for generating a random
> element of a group of order q for use in cryptograpnhy* is the subject of a
> patent, filed in 2000, https://www.google.com/patents/US7372961.
> Blackberry is asserting it (among others that I haven't looked at) against
> Avaya.

That patent link says that it has a priority date of Dec 27, 2000 (with a
disclaimer that Google has not performed a legal analysis to come up with that
date).

The Gnu GMP library version 3.0.1 source code at https://ftp.gnu.org/gnu/gmp/
tarball https://ftp.gnu.org/gnu/gmp/gmp-3.0.1.tar.gz date stamped 2000-04-07
in file gmp-3.0.1/mpz/urandomm.c uses that algorithm for function mpz_urandomm

Later versions of GMP have the improvement of iterating a maximum number of
times then return the value mod n if it doesn't get a result less than n by
then, but that improvement does not appear in the patent claims.


 Sidney Markowitz