MersenneTwister

(English readers scroll down a little bit...)
No sé si este es el lugar apropiado para enviar esto. Hace un tiempo
porté parcialmente el MersenneTwister desde un fuente C++ muy muy feo,
sucio, malo, etc. a VisualSmalltalk. No recuerdo porqué lo hice, capaz
que estaba con fiebre o algo así... como sea, ¿le sirve a alguien
esto acá?

Hello. I don't know if this is the right place for posting this. Some
time ago I've partially ported the MersenneTwister from an ugly, dirty
and bad C++ source to VisualSmalltalk. I don't know why I've done that,
maybe I was sick or something... anyway, it is useful to anybody here?

Mersenne Twister Home Page:
http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html




_______________________________________________
Cryptography mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/cryptography

Hi Hernán,

Thank you for your question.  I just spent some time looking it up and I
found this in wikipedia.  http://en.wikipedia.org/wiki/Mersenne_twister 

"Application
Unlike Blum Blum Shub, the algorithm in its native form is not suitable for
cryptography. Observing a sufficient number of iterates (624 in the case of
MT19937) allows one to predict all future iterates. Combining the Mersenne
twister with a hash function solves this problem, but slows down generation.

"Another issue is that it can take a long time to turn a non-random initial
state into output that passes randomness tests, due to its size. A small
Lagged Fibonacci generator or Linear congruential generator gets started
much quicker and is usually used to seed the Mersenne Twister. If only a few
numbers are required and standards aren't high it is simpler to use the seed
generator. But the Mersenne Twister will still work.

"For many other applications, however, the Mersenne twister is fast becoming
the random number generator of choice. Since the library is portable, freely
available and quickly generates good quality random numbers it is rarely a
bad choice.

"It is designed with Monte carlo simulations and other statistical
simulations in mind. Researchers primarily want good quality numbers but
also benefit from its speed and portability."

Notice that it says that the PRNG is not appropriate for Cryptographic
applications because of the possibility of retrieving a sequence that is
predictable.  

Because of this I would say that the Cryptography Repository may not be the
right place to put this.  If you would like some help creating a separate
repository for this code I would be happy to help you.

What does everyone else think about including this PRNG in the Cryptography
Repository?  I suppose that we could include a warning not to use this for
cryptographic applications.

Thoughts?  

Thanks,

Ron Teitelbaum
Squeak Cryptography Team Leader


_______________________________________________
Cryptography mailing list
[hidden email]
http://lists.squeakfoundation.org/cgi-bin/mailman/listinfo/cryptography