gap-io 4.5.1+ds-1 / usr / share / gap / pkg / io / doc / chap6.txt

  
  6 Really random sources
  
  This  section describes so called real random sources. It is an extension to
  the  library  mechanism  of  random  source  objects  that  uses the devices
  /dev/random  and /dev/urandom available on Linux systems (and maybe on other
  operating  systems) providing random numbers that are impossible to predict.
  The  idea  is  that  such  sources  of  random numbers are useful to produce
  unpredictable secret keys for cryptographic applications.
  
  
  6.1 The functions
  
  6.1-1 RandomSource
  
  RandomSource( r, dev )  method
  Returns:  a real random source object or fail
  
  The  first  argument  r  must  be  the GAP filter IsRealRandomSource and the
  second  either the string random or the string urandom. A real random source
  object  is  created  that  draws  its random numbers from the kernel devices
  /dev/random  and  /dev/urandom  respectively.  Whereas  /dev/urandom  always
  provides  random  numbers  of not guaranteed quality, the device /dev/random
  measures its entropy and produces guaranteed unpredictable numbers. However,
  it  might  block until enough random events (like mouse movements) have been
  accumulated.