Saturday, July 02 2005 @ 03:50 AM EDT Contributed by: glosser
The NewsForge presents this tutorial on securing email.
With governments and law enforcement organizations pushing for increasingly intrusive monitoring and logging of business email messages, network administrators are put in an uncomfortable situation. Even disregarding privacy implications, such systems pose security problems at least as serious as those they attempt to solve. A "master archive" of emails is after all an extremely tempting target to external hackers, but it also has staggering potential for internal abuse. Ideally, we would want no centralized mail logs, but legal and corporate requirements mandate suitable record-keeping in the case of an internal or external audit. One way to meet both goals is by encrypting the archive using public key cryptography.
While traditional cryptographic systems can be thought of as safes -- secure places where one can put or retrieve things with the help of the appropriate key -- public key cryptographic systems are more akin to mailboxes, where practically anybody can drop things in, but only someone with a key can retrieve them. The key (no pun intended) difference is that public key cryptography uses two different keys. One key, known as the public key, encrypts files, and another, the secret key, decrypts them.
As its name suggest, a public key can be distributed as widely as you need. Encrypted material will remain unreadable to anyone without the secret key. This is exactly what we need to set up a relatively benign email archive: to make it straightforward to add material to, but impossible to access without the required key.
