Draft Special Publication 800-90A Recommendation for Random Number Generation Using Determiniatic Random Bit Generators. This is intended as a revision of the currently-posted version of SP 800-90. Two of the appendices in SP 800-90 provided information on entropy sources and RBG constructions. These topics will be discussed in further detail in SP 800-90B and SP 800-90C, respectively, which are under development. SP 800-90A takes into account the work on RBGs that has been conducted within Accredited Standards Committee X9 since the original publication of SP 800-90.