NAME    random - Blum-Blum-Shub pseudo-random number generatorSYNOPSIS    random([[min, ] max])TYPES    min		integer    max		integer    return	integerDESCRIPTION    Generate a pseudo-random number using a Blum-Blum-Shub generator.    We return a pseudo-random number over the half closed interval [min,max).    By default, min is 0 and max is 2^64.    While the Blum-Blum-Shub generator is not painfully slow, it is not    a fast generator.  For a faster, but lesser quality generator    (non-cryptographically strong) see the additive 55 generator    (see the rand help page).    Other arg forms:	random()	Same as rand(0, 2^64)	random(max)	Same as rand(0, max)    The random generator generates the highest order bit first.	 Thus:	random(256)    will produce the save value as:	(random(8) << 5) + random(32)    when seeded with the same seed.    The basic idea behind the Blum-Blum-Shub generator is to use    the low bit bits of quadratic residues modulo a product of    two 3 mod 4 primes.	 The lowest int(log2(log2(p*q))) bits are used    where log2() is log base 2 and p,q are two primes 3 mod 4.    The Blum-Blum-Shub generator is described in the papers:	Blum, Blum, and Shub, "Comparison of Two Pseudorandom Number	Generators", in Chaum, D. et. al., "Advances in Cryptology:	Proceedings Crypto 82", pp. 61-79, Plenum Press, 1983.	Blum, Blum, and Shub, "A Simple Unpredictable Pseudo-Random	Number Generator", SIAM Journal of Computing, v. 15, n. 2,	1986, pp. 364-383.	U. V. Vazirani and V. V. Vazirani, "Trapdoor Pseudo-Random	Number Generators with Applications to Protocol Design",	Proceedings of the 24th	 IEEE Symposium on the Foundations	of Computer Science, 1983, pp. 23-30.	U. V. Vazirani and V. V. Vazirani, "Efficient and Secure	Pseudo-Random Number Generation", Proceedings of the 24th	IEEE Symposium on the Foundations of Computer Science,	1984, pp. 458-463.	U. V. Vazirani and V. V. Vazirani, "Efficient and Secure	Pseudo-Random Number Generation", Advances in Cryptology -	Proceedings of CRYPTO '84, Berlin: Springer-Verlag, 1985,	pp. 193-202.	Sciences 28, pp. 270-299.	Bruce Schneier, "Applied Cryptography", John Wiley & Sons,	1st edition (1994), pp 365-366.    This generator is considered 'strong' in that it passes all    polynomial-time statistical tests.	The sequences produced are    random in an absolutely precise way.  There is absolutely no better    way to predict the sequence than by tossing a coin (as with TRULY    random numbers) EVEN IF YOU KNOW THE MODULUS!  Furthermore, having    a large chunk of output from the sequence does not help.  The BITS    THAT FOLLOW OR PRECEDE A SEQUENCE ARE UNPREDICTABLE!    Of course the Blum modulus should have a long period.  The default    Blum modulus as well as the compiled in Blum moduli have very long    periods.  When using your own Blum modulus, a little care is needed    to avoid generators with very short periods.  See the srandom()    help page for information for more details.    To compromise the generator, an adversary must either factor the    modulus or perform an exhaustive search just to determine the next    (or previous) bit.	If we make the modulus hard to factor (such as    the product of two large well chosen primes) breaking the sequence    could be intractable for todays computers and methods.    The Blum generator is the best generator in this package.  It    produces a cryptographically strong pseudo-random bit sequence.    Internally, a fixed number of bits are generated after each    generator iteration.  Any unused bits are saved for the next call    to the generator.  The Blum generator is not too slow, though    seeding the generator via srandom(seed,plen,qlen) can be slow.    Shortcuts and pre-defined generators have been provided for this    reason.  Use of Blum should be more than acceptable for many    applications.    The goals of this package are:	all magic numbers are explained	    I distrust systems with constants (magic numbers) and tables	    that have no justification (e.g., DES).  I believe that I have	    done my best to justify all of the magic numbers used.	 full documentation	    You have this source file, plus background publications,	    what more could you ask?	large selection of seeds	    Seeds are not limited to a small number of bits.  A seed	    may be of any size.	the strength of the generators may be tuned to meet the need	    By using the appropriate seed and other arguments, one may	    increase the strength of the generator to suit the need of	    the application.  One does not have just a few levels.    For a detailed discussion on seeds, see the srandom help page.    It should be noted that the factors of the default Blum modulus    is given in the source.  While this does not reduce the quality    of the generator, knowing the factors of the Blum modulus would    help someone determine the next or previous bit when they did    not know the seed.	If this bothers you, feel free to use one    of the other compiled in Blum moduli or provide your own. See    the srandom help page for details.EXAMPLE    ; print srandom(0), random(), random(), random()    RANDOM state 9203168135432720454 13391974640168007611 13954330032848846793    ; print random(123), random(123), random(123), random(123), random(123)    22 83 66 88 67    ; print random(2,12), random(2^50,3^50), random(0,2), random(-400000,120000)    10 483381144668580304003305 0 -70235LIMITS    min < maxLINK LIBRARY    void zrandom(long cnt, ZVALUE *res)    void zrandomrange(ZVALUE low, ZVALUE high, ZVALUE *res)    long irandom(long max)SEE ALSO    seed, srand, randbit, isrand, rand, srandom, israndom## Copyright (C) 1999  Landon Curt Noll#### Calc is open software; you can redistribute it and/or modify it under## the terms of the version 2.1 of the GNU Lesser General Public License## as published by the Free Software Foundation.#### Calc is distributed in the hope that it will be useful, but WITHOUT## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY## or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU Lesser General## Public License for more details.#### A copy of version 2.1 of the GNU Lesser General Public License is## distributed with calc under the filename COPYING-LGPL.  You should have## received a copy with calc; if not, write to Free Software Foundation, Inc.## 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA.#### @(#) $Revision: 29.3 $## @(#) $Id: random,v 29.3 2006/05/07 07:25:46 chongo Exp $## @(#) $Source: /usr/local/src/cmd/calc/help/RCS/random,v $#### Under source code control:	1997/02/17 01:18:22## File existed as early as:	1997#### chongo <was here> /\oo/\	http://www.isthe.com/chongo/## Share and enjoy!  :-)	http://www.isthe.com/chongo/tech/comp/calc/