Bernstein v. the U.S. Department of State, landmark legal decision (1996) that set two important precedents in the field of digital technology. First, it ruled that U.S. government regulations that barred the export of encryption software were unconstitutionally restrictive; second, it declared that software source code can be a form of protected free speech.

In the lawsuit a federal court was asked to rule in a dispute between the U.S. government and Daniel Bernstein, a mathematics professor at the University of Illinois at Chicago, to determine if he had the right to distribute encryption software of his own creation over the Internet. Bernstein had devised his encryption program, called Snuffle, in 1990 while he was a Ph.D. candidate at the University of California, Berkeley. His software converted a one-way “hash function” (one that takes an input string of arbitrary length and compresses it into a finite, usually shorter, string; the function has many uses in cryptography) into a private-key encryption system (one that can be decoded only by whoever holds the private “key,” or pass code). The functionality of the software depended on two people’s having exchanged their private keys.

Bernstein used Snuffle while teaching a course on cryptography to convey his ideas about encryption. He made the software source code available free on the Web site where he placed course-review materials for his classes. Wanting to disburse the material farther to the academic and scientific communities, in the mid-1990s Bernstein asked the U.S. State Department if he would need a license to publish Snuffle. He was told that his creation was tantamount to “munitions” under International Traffic in Arms Regulations (ITAR). Therefore, the government contended, Bernstein would have to obtain export licenses from the State Department for each person outside the United States who wanted to view Snuffle’s online source code.

In February 1995, with the help of a legal team from the Electronic Frontier Foundation, Bern