Pro PHP Security: From Application Security Principles to the Implementation of XSS Defenses, Second Edition

Recommended Encryption Algorithms

Although building effective encryption into an application is extremely difficult to get right, there are, thanks to the efforts of open-minded cryptographers, free software implementations that anyone can use, such as the mcrypt and OpenSSL libraries—anyone, that is, not affected by legal restrictions on the import or use of cryptographic software. (Remember that cryptographic algorithms may be viewed as weaponry by the United States government and others; see our summary of this issue at the end of this chapter.)

Encryption libraries, like the two mentioned previously, often contain a bewildering array of options and modes, and more than a few different algorithms. Some algorithms may be included for historical ...