Web Security

Chapter 11

Encryption Algorithms and Random Numbers

An encryption algorithm and a pseudorandom number algorithm are methods often used in program development, but an encryption algorithm is very professional; in web development, if we have a lack of understanding of cryptographic algorithms and pseudorandom number algorithms, we are likely to incorrectly use them and eventually cause safety problems. In this chapter, we will discuss some of the common problems.

11.1 Introduction

Cryptography has a long history, and it is meant to meet people’s most basic security need—confidentiality. Cryptography is the basis for the development of the field on security (Figure 11.1).

Figure 11.1

The Da Vinci Code barrel.

In web applications, we can often ...