Right, there used to be a number of different random devices, including random, arandom, urandom, prandom, and srandom. Prandom was killed quite some time ago,

Right, there used to be a number of different random devices, including random, arandom, urandom, prandom, and srandom. Prandom was killed quite some time ago, and as of 2011 all the rest are unified. Four /dev nodes still exist for compatibility, but they all behave identical; so there's really just one random device. The principle being that there's good randomness and there's good randomness. The system does its best to provide good randomness. You can't choose the wrong device.