Web Security, Privacy & Commerce, 2nd Edition

Legal Restrictions on Cryptography

The legal landscape of cryptography is complex and constantly changing. In recent years the legal restrictions on cryptography in the United States have largely eased, while the restrictions in other countries have increased somewhat.

In this section, we’ll examine restrictions that result from patent law, trade secret law, import/export restrictions, and national security concerns.

Tip

These regulations and laws are in a constant state of change, so be sure to consult with a competent attorney (or three) if you will be using cryptography commercially or internationally.

Cryptography and the Patent System

Patents applied to computer programs, frequently calledsoftware patents , have been accepted by the computer industry over the past thirty years—some grudgingly, and some with great zeal.

Some of the earliest and most important software patents granted by the U.S. Patent and Trademark Office were in the field of cryptography. These software patents go back to the late 1960s and early 1970s. Although computer algorithms were widely thought to be unpatentable at the time, the cryptography patents were allowed because they were written as patents on encryption devices that were built with hardware—computers at the time were too slow to perform meaningfully strong encryption in a usably short time. IBM’s original patents on the algorithm that went on to become the U.S. Data Encryption Standard (DES) were, in fact, on a machine that implemented the encryption ...