Computer networks are used more and more for the transmission of information data. This includes personal data which need to be well-protected. The use of cryptography is well suited for this.


Cryptography can make a data file unreadable. Only the matching key can return it to its original form.

A good article with a lot of background information on cryptography is:

Three WWW pages with much information are: Frequently asked question are answered in the Cryptography FAQ. Developments and discussions can be followed in the newsgroup talk.politics.crypto.

More information on the privacy group of DB.NL can be found in our own page.

How much the citizen can use cryptography in the future depends heavily on the plans of the government to restrict cryptography. In the Netherlands, the use of personal details is guarded by the socalled Registration Chamber. They see technology as a solution to the through technology induced registration fever.

Pretty Good Privacy (PGP)

If privacy is outlawed, only outlaws will have privacy.
-- Philip Zimmermann
PGP is a strong encryption program which is available for many systems and for completely no charge. The program has been controversial in the USA, because there were a few legal complications.

These problems have been solved with the arrival of MIT PGP 2.6 for use in the USA, and PGP 2.6ui for the rest of the world. PGP 2.6ui is compatible with both MIT PGP 2.6 and the old version PGP 2.3a.

More information can be found in:

See also Zimmermann's Testimony.

The manuals for PGP, Essential topics and Special topics, are elaborate, but not easy. Other, easier manuals are:

You can place your own public key onto the PGP-keyserver-netwerk and search for the keys of others.

For more information, see the list with PGP FAQ's and the newsgroup


RSA Data Security Inc. developed applications of cryptography. The RSA encryption algoritm was used here, which is regarded as virtually unbreakable. The company also offers licences to other companies.

See also two press releases on the application of RSA.

Much informaton on RSA can be found in the RSA FAQ.


A digitized picture usually contains an amount of noise, just like sound. Steganography is replacing this noise with information, which would allow hidden information to be transmitted.

Romana Machado wrote the program Stego for this.

This program is available for MacIntosh and MS-DOS computers.


With a remailer it is possible to send mail anonymously, or to post into a newsgroup. A remailer removes all identifyable data from the header of a message sent to it, and subsequently passes it on. One step further is to first encrypt the message with PGP, after which the remailer decrypts it again and passes it on. The list with remailers contains information on the various remailers.

For the smaller messages you can use the remailer op het World Wide Web.

Telephone services

PTT Telecom offers more and more services. One of these to be introduced next year is the number identification, where the caller issues his telephone number.


The Clipper chip

The US government has developed a chip with which telephone conversations can be encrypted. With this it would be impossible to listen in to telephone conversations, except by the government which has the key for each chip.

The export ban on cryptography

The export of (strong) cryptography is forbidden in the USA. This will also have an impact on us if some particular forms of cryptography is going to be be permitted.

More information on privacy can be found in the Privacy FAQ. There is also a newsgroup alt.privacy and a Privacy Forum.