Web Security, Privacy & Commerce, 2nd Edition

Chapter 4. Cryptography and the Web

When you get right down to it, the Internet is an unsecure communications system. While the Internet was designed to be efficient and robust, it was not designed to be inherently secure. The Internet’s original security was provided by simple access control: only trustworthy military installations, corporations, and schools were allowed to have access. At each of those organizations, only trustworthy individuals were allowed to have accounts. In theory, people who abused the network lost their access.

The idea of using access control to ensure security failed almost immediately. In December 1973, Robert Metcalfe noted that high school students had gained access to the Internet using stolen passwords; two computers had crashed under suspicious circumstances. In RFC 602 (reprinted on the following page) Metcalfe identified three key problems on the network of his day: sites were not secure against remote access; unauthorized people were using the network; and some ruffians were breaking into computers (and occasionally crashing those machines) simply for the fun of it.

Today, the Internet’s overall security posture has changed significantly. As we saw in Chapter 2, the simple act of browsing a web page on a remote computer can involve sending packets of information to and receiving them from more than a dozen different computers operated by just as many different organizations. The division of responsibility among multiple organizations makes it possible ...