The subject of elliptic curves encompasses a vast amount of mathematics. Our aim in this section is to summarize just enough of the basic theory for cryptographic applications. For additional reading, there are a number of survey articles and books devoted to elliptic curve cryptography [14, 68, 81, 135], and many others that describe the number theoretic aspects of the theory of elliptic curves, including [25, 65, 73, 74, 136, 134, 138].