# Multiple Instance of rand? **URL:** \ **Category:** Ruby\ **Created:** [June 25, 2007, 1:56pm UTC](https://www.ruby-forum.com/t/multiple-instance-of-rand/107695 "2007-06-25T13:56:40Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![are](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/d07c76/32.png) [@are](https://www.ruby-forum.com/u/are)\ **Post date:** [June 25, 2007, 1:56pm UTC](https://www.ruby-forum.com/t/multiple-instance-of-rand/107695/1 "2007-06-25T13:56:40Z")
Is it possible to have multiple instances Ruby’s random-number generator running within one program? I would like to have different random sequences, each with its own seed. ---
**Author:** ![are](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/d07c76/32.png) [@are](https://www.ruby-forum.com/u/are)\ **Post date:** [June 25, 2007, 7:35pm UTC](https://www.ruby-forum.com/t/multiple-instance-of-rand/107695/2 "2007-06-25T19:35:14Z")
are wrote: > Is it possible to have multiple instances Ruby’s random-number > generator running within one program? I would like to have different > random sequences, each with its own seed. Not yet, but it has been proposed for 1.9. The best workaround for now is to use one of the external PRNG libraries. ---
**Author:** ![are](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/d07c76/32.png) [@are](https://www.ruby-forum.com/u/are)\ **Post date:** [June 26, 2007, 3:16pm UTC](https://www.ruby-forum.com/t/multiple-instance-of-rand/107695/3 "2007-06-26T15:16:34Z")
On 26/06/07, are [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Thanks much. I’m kind of a noob; could you please give me a hint as > to what the PRNG libraries are and where I would find them? Try searching within these sites: [http://rubyforge.org/](http://rubyforge.org/) [http://raa.ruby-lang.org/](http://raa.ruby-lang.org/) ---
**Author:** ![are](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/d07c76/32.png) [@are](https://www.ruby-forum.com/u/are)\ **Post date:** [June 26, 2007, 12:51pm UTC](https://www.ruby-forum.com/t/multiple-instance-of-rand/107695/4 "2007-06-26T12:51:12Z")
Thanks much. I’m kind of a noob; could you please give me a hint as to what the PRNG libraries are and where I would find them? ---
**Author:** ![are](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/d07c76/32.png) [@are](https://www.ruby-forum.com/u/are)\ **Post date:** [June 26, 2007, 4:24pm UTC](https://www.ruby-forum.com/t/multiple-instance-of-rand/107695/5 "2007-06-26T16:24:39Z")
> Thanks much. I’m kind of a noob; could you please give me a hint as > to what the PRNG libraries are and where I would find them? A PRNG is a pseudo random number generator - “pseudo” here expresses the fact that a computer is a deterministic device, so some tweaking is necessary to make it difficult to predict the next “random” number … You can get an implementation for Ruby here: [http://rubyvm.sourceforge.net/subprojects/randomr/](http://rubyvm.sourceforge.net/subprojects/randomr/) Best regards, Axel ---
**Author:** ![are](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/d07c76/32.png) [@are](https://www.ruby-forum.com/u/are)\ **Post date:** [June 26, 2007, 4:58pm UTC](https://www.ruby-forum.com/t/multiple-instance-of-rand/107695/6 "2007-06-26T16:58:42Z")
On Tue, 26 Jun 2007, are wrote: > Thanks much. I’m kind of a noob; could you please give me a hint as > to what the PRNG libraries are and where I would find them? There is [http://rubyforge.org/projects/crypt-isaac](http://rubyforge.org/projects/crypt-isaac) ISAAC is a cryptographically secure PRNG (the mersenne twister, which is what Ruby uses, produces quality streams of numbers, butis not cryptographically secure). That is a pure Ruby implementation. I have a version that has a C extension that I have been sitting on for quite some time. I’ll make some time today to get that version packaged and uploaded, though. Kirk H.