A Child-safe Internet
By ColmSmyth on Dec 10, 2004
It's tough for parents today; the internet has so much to offer children, but also a lot of adult and inappropriate content.
However the European Union is providing 60m Euro in funding to provide parents and teachers with tools to keep their children safe while on the internet. It's likely that these tools will be based on open-source, so they will be usable world-wide.
It's already possible to use free tools to do this today, but it's not yet easy enough. The key terms that you encounter with web or mail filtering are whitelist and blacklist; a whitelist or YES-list is a list of good sites/addresses that are allowed through, a blacklist or NO-list is a list of known bad sites. If you want the safest solution, you can use a whitelist and prevent anything that is not on that list from coming through. A blacklist is typically only useful if you subscribe to an update service (similar to virus protection); even with regular updates they can never be entirely safe, so I don't recommend them. It is also possible to use filters that look for keywords in the address name or in the content; if your list of keywords is long enough, this is far safer.
Here are some specific tools you might like to take a closer look at:
- A web proxy such as the popular Squid can stop inappropriate content as well as caching content for faster access; DansGuardian is far easier to use and supports keyword-based filters
- For blocking spam and adult mail, Postfix is an advanced mail-processing program similar to the popular sendmail; it supports a variety of techniques for stopping inappropriate mail or spam; for example, see this Newsforge article which uses a Postfix after content filter
Most free tools work best on UNIX-based systems such as Linux and Solaris. If your children use Windows, you can setup a separate machine to act as an internet gateway.
But if you're not interested in technology, there are several good sites where you can get more advice; the Filtering Software site contains reviews of several easy-to-use packages, and Phil Bradleys's Child Safe Internet has a host of links and useful information.