Secrecy in Communications

Abstract

One goal of this chapter is to explore dynamic secrets from a theoretic point of view. We use a Venn diagram to illustrate the difference between dynamic secrets and the traditional perception of a secret key. The Venn diagram analysis shows that the communication process itself can be a rich source of secrecy. This source was ignored in traditional key management. Dynamic secrets make use of this secrecy source and keep refilling secrecy to a dynamic key. As a result, dynamic keys are more resilient to cracking and stealing than traditional secret keys.

Another goal of this chapter is to establish connections between dynamic secrets and various other theoretical research areas. The discussion in this chapter involves information theoretic measures such as Shannon entropy and R$\acute{e}$nyi entropy. We include intuitive interpretations to these measures in this chapter and leave the formal definitions in the appendix.