Cryptology in Transition
This work is intended to convey to the reader the phase of transition that public cryptology is in at the present time and the evolving state of the art. The transition is multifaceted: In scope of relevancy it has evolved from a government monopoly dealing with military and diplomatic communications to a major concern of business in general, the banking industry in particular, and, more recently, the public at large. Its technology has expanded from paper-andpencil and various mechanical devices to large, high-speed, electronic computers. Its security emphasis has changed from statistical uncertainty to computational complexity. And last, but not least, in concept it has developed from conventional, private-key schemes to public-key cryptosystems providing instant privacy and twoway authentication. This latest transition also reflects the rapidly evolving state of the "art" of cryptology. Since its recent adoption by the