Hardware Random Number Generator

The advantage of hardware random number generators are:

  1. Higher security level

  2. Better random numbers

  3. Faster

Important

The following might show no difference since modern kernels mix all different (and there are many) number generators to feed /dev/random

Modern kernels have a random number generator entropy pool

In the age of cyber security, hardware random generators became a standard

CPU's, Network interfaces, TPM security chips contain hardware random number generators and can be enabled in the kernel. Dedicated hardware might be available and be accessed via a kernel module as intel-rng. This produces /dev/hwrng

For Gentoo Linux emerge rng-tools this gives programs as rngtest , randstat and the configuration file /etc/conf.d/rngd

rngd -dt is a first test to see if the user space daemon is happy

Start the service /etc/init.d/rngd restart

cat /dev/random | rngtest -c 1000 or rngtest -c 100 < /dev/hwrng is how rngtest is used

dd if=/dev/random of=/dev/null bs=1024 count=1 iflag=fullblock should return immediately if there is one of the many hardware random number generators

randstat is a program that returns the same as cat /proc/sys/kernel/random/entropy_avail

Add it to boot service rc-update add rngd boot

An other test is cat /dev/hwrng or with or without hardware random number generator cat /dev/random or cat /dev/urandom to stop Ctrl+C


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