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Re: Seeding random() randomly
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Re: Seeding random() randomly


  • Subject: Re: Seeding random() randomly
  • From: Jens Alfke <email@hidden>
  • Date: Thu, 26 May 2011 20:32:48 -0700

On May 26, 2011, at 7:15 PM, Kevin Bracey wrote:

> srandom(time(NULL));

It’s never a good idea to seed a RNG with something guessable like this. (An old exploit against the Netscape browser’s SSL implementation was made possible in part by doing exactly that.)

All you have to do is call srandomdev() once; that will seed the generator used by random() with some extremely random (“high-entropy”) data read from /dev/random, which is generated by the kernel through all kinds of black magic.

—Jens

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References: 
 >Re: Seeding random() randomly (From: Kevin Bracey <email@hidden>)

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