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Full Discussion: generating 16 digit random number in C
Top Forums Programming generating 16 digit random number in C Post 302344705 by matrixmadhan on Monday 17th of August 2009 10:57:05 AM
Old 08-17-2009
From man pages, random seem to be more suitable for key generation than urandom character stream

Quote:
When read, the /dev/random device will only return random bytes within
the estimated number of bits of noise in the entropy pool. /dev/random
should be suitable for uses that need very high quality randomness such
as one-time pad or key generation
 

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LEARN ABOUT OPENSOLARIS

srand

rand(3UCB)					     SunOS/BSD Compatibility Library Functions						rand(3UCB)

NAME

       rand, srand - simple random number generator

SYNOPSIS

       /usr/ucb/cc [ flag ... ] file ...

       int rand();

       int srand(seed)
       unsigned seed;

DESCRIPTION

       rand()  uses a multiplicative congruential random number generator with period 2^32 to return successive pseudo-random numbers in the range
       from 0 to 2^31 -1.

       srand() can be called at any time to reset the random-number generator to a random starting point. The generator is initially seeded with a
       value of 1.

SEE ALSO

       cc(1B), drand48(3C), rand(3C), random(3C)

NOTES

       Use of these interfaces should be restricted to only applications written on BSD platforms.  Use of these interfaces with any of the system
       libraries or in multi-thread applications is unsupported.

       The spectral properties of rand() leave a great deal to be desired. drand48(3C) and random(3C) provide much better, though more	elaborate,
       random-number generators.

       The low bits of the numbers generated are not very random; use the middle bits. In particular the lowest bit alternates between 0 and 1.

SunOS 5.11							    30 Oct 2007 							rand(3UCB)
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