Java Network Programming, 3rd Edition

Chapter 11. Secure Sockets

One of the perennial fears of consumers buying goods over the Internet is that some hacker will steal their credit card number and run up a several-thousand-dollar bill by calling phone sex lines. In reality, it’s more likely that a clerk at a department store will read their credit card number from a store receipt than that some hacker will grab it in transit across the Internet. In fact, as of mid-2004, the major online thefts of credit card numbers have been accomplished by stealing the information from poorly secured databases and filesystems after the information has been safely transmitted across the Internet. Nonetheless, to make Internet connections more fundamentally secure, sockets can be encrypted. This allows transactions to be confidential, authenticated, and accurate.

However, encryption is a complex subject. Performing it properly requires a detailed understanding not only of the mathematical algorithms used to encrypt data but also of the protocols used to exchange keys and encrypted data. Even a small mistake can open a large hole in your armor and reveal your communications to an eavesdropper. Consequently, writing encryption software is a task best left to experts. Fortunately, nonexperts with only a layperson’s understanding of the underlying protocols and algorithms can secure their communications with software designed by experts. Every time you order something from an online store, chances are the transaction is encrypted and authenticated ...