Java Cryptography

Chapter 2. Concepts

At the application programming level, there are many options for making a program secure. Cryptography is the biggest, baddest tool in the application programmer’s arsenal. But it is important to realize that a cryptographically enabled program is not necessarily a secure one. Without a carefully planned and constantly scrutinized security strategy, cryptography won’t do you much good.

Correctly used, cryptography provides these standard security features:

• Confidentiality assures you that data cannot be viewed by unauthorized people.

• Integrity assures you that data has not been changed without your knowledge.

• Authentication assures you that people you deal with are not imposters.

Random numbers are used in many cryptographic algorithms. I’ll talk a little bit about computer-generated random numbers at the end of the chapter. I’ll wrap up by discussing the cryptographic algorithms used in this book.