This Day in History
September 20, 1983
RSA Algorithm patent is awarded
The RSA algorithm, one of the world's most widely-used encryption methods, had been developed in 1977. Scientific American columnist Martin Gardner wrote a description of the algorithm in his "Mathematical Games" column, mentioning that readers could send a self-addressed stamped envelope to receive a copy of the MIT Technical memorandum describing it. More than three thousand people sent envelopes, though they did not receive their copies of the papers until after the patent was issued six years later due to members of the National Security Agency (NSA) raising questions about the legality of making the information available.