Harvard Law School > Berkman Center > Open Education > Cyberprivacy > Self-Help > Privacy Enhancing Technologies > Examples >

PRIVACY IN CYBERSPACE

Privacy Enhancing Technologies

Example Technologies

Following are some prominent examples of Privacy Enhancing Technologies that have emerged from the free software and open source movements. This list is by no means comprehensive, but instead should serve to give the reader a “flavor” for the sorts of self-help available. For the most part, none of these examples require special technical skills on the part of the user.

Other technologies based specifically on cryptography that enhance privacy and anonymity are discussed in the cryptography applications section of this module.

Mozilla and its progeny: Mozilla is a whole platform of open source projects. Mozilla includes several privacy enhancing features by default, including the ability to block banner ads and pop-ups, better cookie control and provides a framework for independent developers to provide their own privacy enhancing plug-ins, for example:
- AdBlock: Enables users to filter banner ads and other images.
- CookieHelp: Understanding the contents of a cookie filei.
Privoxy: protects user against undesired disclosure and also unwanted advertisments or pop-ups. Privoxy is a web proxy with advanced filtering capabilities for protecting privacy, filtering web page content, managing cookies, controlling access, and removing ads, banners, pop-ups and other “obnoxious Internet junk.” Privoxy has a very flexible configuration and can be customized to suit individual needs and tastes. Privoxy has application for both stand-alone systems and multi-user networks.
Mixmaster: Mixmaster is a secure remailer program. It is an open source project. Email sent through mixmaster is routed through many nodes to obscure its origin, and relies on cryptography to insure that the message is unchanged (see cryptography section below, and description of invisiblog.com). As more people join the mixmaster network, it becomes easier to route your email through many nodes and better protect the original author’s identity. See the Mixmaster FAQ and the Anonymous Remailer FAQ:

A remailer is a computer service which privatizes your e-mail. A remailer is in sharp contrast to the average Internet Service Providers [ISP] which is terribly anti-private. In fact, ISP could equally stand for “Internet Surveillance Point”.
Traditionally, a remailer allowed you to send electronic mail to a Usenet news group, or to a person, without revealing your true name or e-mail address to the recipient. Today, new web-based remailers permit you to send mail using your real name (if you wish), while protecting your email records from the snooping eyes of your Internet Service Provider.
In the first version of this FAQ (published in 1995), all popular remailers were free-of-charge. Today, a number of services either charge user fees, or support themselves via advertisers.
Anonymizer: Not a free software project, but rather a proxy server that allows you to browse websites without revealing your original IP address. The technology is trivial, however, and exists in many free software projects that perform the same service, e.g. anon-proxy.
Spamassassin: a highly effective spam filter; configured properly it returns an extremely low rate of false positives, and very few false negatives.
Vipul’s Razor: collaborative, peer-to-peer spam filter; allows users to flag spam for other users. Collaboration occurs not just in the development of the software but in building a large, trustworthy spam databaes.
New York Times Random Login Generator: conveniently generates a random login to the New York Times website to read archived articles without having to register with all your personal information.

There are also a great number of free software/open source security tools, which can protect against identity theft, cracker attacks, and other malicious entities. GNU/Linux, the flagship of the free software movement, is significantly more resilient to attack than Microsoft’s operating systems. Most GNU/Linux distributions include many tools to protect the integrity of user’s personal data.

It is also worth discussing privacy enhancing technologies that are not the product of the free software movement:

Digital Cash: Several abortive attempts have been made thus far to create an online currency which would allow people to spend money as anonymously as they now do with paper cash. More information at the Digital Cash mini-FAQ:
Anonymous digital cash works just like real paper cash. Once anonymous digital cash is withdrawn from an account, it can be spent or given away without leaving a transaction trail. You create anonymous digital cash by using numbered bank accounts and blind signatures rather than fully identified accounts and non-blind signatures.

PRIVACY IN CYBERSPACE

Privacy Enhancing Technologies

Example Technologies

Related Readings