Neal R. Wagner, Marianne R. Magyarik. A Public Key Cryptosystem Based on the Word Problem. In G. R. Blakley, David Chaum, editors, Advances in Cryptology, Proceedings of CRYPTO 84, Santa Barbara, California, USA, August 19-22, 1984, Proceedings. Volume 196 of Lecture Notes in Computer Science, pages 19-36, Springer, 1984. [doi]
Abstract is missing.