WHAT IF your research could help solve a looming national problem, but government officials thought publishing it would be tantamount to treason? A Stanford professor and his graduate students found themselves in that situation 37 years ago, when their visionary work on computer privacy issues ran afoul of the National Security Agency. At the time, knowledge of how to encrypt and decrypt information was the domain of government; the NSA feared that making the secrets of cryptography public would severely hamper intelligence operations. But as the researchers saw it, society’s growing dependence on computers meant that the private sector would also need effective measures to safeguard information. Both sides’ concerns proved prescient; their conflict foreshadowed what would become a universal tug-of-war between privacy-conscious technologists and security-conscious government officials.