ABSTRACT
The theme of this chapter concerns public-key cryptosystems based on the Discrete Logarithm problem. The first and best-known of these is the ElGamal Cryptosystem. The Discrete Logarithm problem forms the basis of numerous cryptographic protocols that we will study throughout the rest of the text. Thus we devote a considerable amount of time to discussion of this important problem. In later sections of this chapter, we give treatments of some other ElGamal-type systems based on finite fields and elliptic curves.
