Public-key cryptography in functional programming context

Cryptography is the science of information and communication security. Up to now, for efficiency reasons cryptographic algorithm has been written in an imperative language. But to get acquaintance with a functional programming language a question arises: functional programming offers some new for secure communication or not? This article investigates this question giving an overview on some cryptography algorithms and presents how the RSA encryption in the functional language Clean can be implemented and how can be measured the efficiency of a certain application. 1 Functional programming Functional programming is based on the lambda-calculus, with its main principle developed in 1930, by Alonzo Church and Stephen Cole Kleene. With lambda-calculus we can define the notion of computable function, and using the rules defined by lambda-calculus we can express and evaluate any computable function. But in the early development stage of computer science the computer calculating mechanisms were based on another calculating model, such as a Turing machine’s. The Turing machine functioning mechanism was described in 1936 by the mathematician Alan Turing, in the same time as lambda calculus. The Turing machine was the base of Neumann’s architecture Computing Classification System 1998: D.1.1 Mathematics Subject Classification 2010: 68N18