Topic summary
Entropy source
Extracted from the Wikipedia article Hardware random number generator.
Performance test
The failure of a TRNG can be quite complex and subtle, necessitating validation of not just the results (the output bit stream), but of the unpredictability of the entropy source. Hardware random number generators should be constantly monitored for proper operation to protect against the entropy source degradation due to natural causes and deliberate attacks. FIPSPub 140-2 and NIST Special Publication 800-90B define tests which can be used for this.