Random Number Generators Founded on Signal and Information Theory

The strength of a cryptographic function depends on the amount of entropy in the cryptovariables that are used as keys. Using a large key length with a strong algorithm is false comfort if the amount of entropy in the key is small. Unfortunately the amount of entropy driving a cryptographic function is usually overestimated, as entropy is confused with much weaker correlation properties and the entropy source is difficult to analyze. Reliable, high speed, and low cost generation of non-deterministic, highly entropic bits is quite difficult with many pitfalls. Natural analog processes can provide nondeterministic sources, but practical implementations introduce various biases. Convenient wide-band natural signals are typically 5 to 6 orders of magnitude less in voltage than other co-resident digital signals such as clock signals that rob those noise sources of their entropy. To address these problems, we have developed new theory and we have invented and implemented some new techniques....

• Type: Conference
• Year: 1999
• Where: CHES
• Authors: David Paul Maher, Robert J. Rance
• Keywords: CHES 1999, Cryptology, Entropy, Entropy Sources, Random Number Generators