Linux Random Number Generator

The venerable Linux /dev/random served users of cryptographic mechanisms well for a long time. Its behavior is well understood to deliver entropic data. In the last years, however, the Linux /dev/random showed signs of age where it has challenges to cope with modern computing environments ranging from tiny embedded systems, over new hardware resources such as SSDs, up to massive parallel systems as well as virtualized environments. This paper proposes a new approach to entropy collection in the Linux kernel with the intention of addressing all identified shortcomings of the legacy /dev/random implementation. The new Linux Random Number Generator’s design is presented and all its cryptographic aspects are backed with qualitative assessment and complete quantitative testing. The test approaches are explained and the test code is made available to allow researchers to re-perform these tests.