Public-key Cryptography: Theory and Practice

B.1. Introduction

Public-key cryptography is not a solution to every security problem. Asymmetric routines are bulky and slow, and, in practice, augment symmetric cryptography by eliminating the need for prior secret establishment of keys between communicating parties. On a workstation of today’s computing technology, this is an interesting and acceptable breakthrough. A 1 GHz processor runs one public-key encryption or key-exchange primitive in tens to hundreds of milliseconds, using at least hundreds of kilobytes of memory. That is reasonable for most applications, given that the routines are invoked rather infrequently.

Now, imagine a situation, where many tiny computing nodes, called sensor nodes, are scattered in an area for the purpose ...