alternative random device

Matthew Byng-Maddick gnupg at
Sun Feb 9 20:51:01 CET 2003

On Sun, Feb 09, 2003 at 01:24:31PM -0600, Richard Laager wrote:
> On Linux, /dev/random is a cryptographically secure* random number
> generate. (* This means it has properties that make it suitable for
> cryptographic operations like key generation that require highly
> random and unpredictable numbers.)

<pedant>/dev/urandom is also (believed to be) cryptographically secure,
because you can't use any arbitrarily sized sequence of bits to know what
the next bits that will come out are (ie. your output doesn't leak information
about your internal state).</pedant>

This doesn't make it suitable for generating long-term keys, however.


Matthew Byng-Maddick         <mbm at> 

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