Dealing a big blow to the federal government’s efforts to maintain tight controls over encryption technology, the Ninth Circuit U.S. Court of Appeals held Thursday that computer source code is speech protected by the First Amendment.

Despite national security concerns, the divided court said that cryptographers can post their encryption programs on the Internet without first getting government approval. The ruling makes unconstitutional U.S. Department of Commerce regulations that require encryption software makers to go through a regulation process that ensures their products are “consistent with U.S. national security and foreign policy interests.”