Sending an e-mail is the equivalent of sending a postcard – anyone can read it. Once an e-mail leaves a computer, it travels over multiple online services and open networks to reach its destination. It can be intercepted and read anywhere during its journey. It can also be read from the numerous backup devices and will be stored by various routing services. For example, co-workers can easily intercept an e-mail sent from an office computer as it travels through the corporate network. In addition, external e-mails travel to and from a computer via an Internet Service Provider (ISP), making ISPs one of the easiest places to intercept traffic. Broadband users share the local loop, which means neighborhood Internet traffic shares the same physical wires. With certain bits of hardware and some know-how, a hacker can easily intercept an e-mail on its way across the local loop. Finally, wireless network traffic is susceptible to interception at the base station for the antenna.
These examples are by no means the only places e-mail can be compromised, and with thousands of hackers on the Internet and so many vulnerable points, never assume an e-mail is private, unless it is encrypted.
Your clients not only need to encrypt their e-mail, but all their sensitive files and data too. They should also be enforcing a security policy aimed at securing their computers against spyware and malicious code to prevent computer-hacking and illegal eavesdropping by hackers and their competitors.
This was first published in December 2005