Official websites use .gov
Secure .gov websites use HTTPS
March 20, 2018
March 2018 Puzzle Periodical - a, b, c - Variable Alphabet Equation
March 2018 NSA Puzzle Periodical - a, b, c - Variable Alphabet Equation by Wendell W.
March 21, 2017
March 2017 Puzzle Periodical - Lucky Seven
March 2017 Puzzle Periodical - Lucky Seven; Puzzle created by David G., NSA Mathematician