TABLE OF CONTENTS The primary goal of a cryptographic security architecture is to safeguard cryptovariables such as keys and related security parameters from misuse. Sensitive data of this kind lies at the heart of any cryptographic system and must be generated by a random number generator of guaranteed quality and security. If the cryptovariable generation process is insecure then even the most sophisticated protection mechanisms in the architecture will do no good. More precisely, the cryptovariable generation process must be subject to the same high level of assurance as the kernel itself if the architecture is to meet its overall design goals, even though it isn't directly a part of the security kernel.
Because of the importance of this process, this entire chapter is devoted to the topic of generating random numbers for use as cryptovariables. The theoretically best means of doing this is to measure physical phenomena such as radioactive decay, thermal noise in semiconductors, sound samples taken in a noisy environment, and even digitised images of a lava lamp. However, few computers (or users) have access to the kind of specialised hardware required for these sources, and must rely on other means of obtaining random data. The term "practically strong randomness" is used here to represent randomness that isn't cryptographically strong by the usual definitions but that is as close to it as is practically possible.
Existing approaches that don't rely on special hardware have ranged from precise timing measurements of the effects of air turbulence on the movement...
