Explore the historical development of public key cryptography in this 49-minute Ernst Weber Lecture from NYU's ECE Seminar Series, presented by Martin E. Hellman. Delve into the evolutionary nature of cryptographic advancements, examining key concepts such as trap doors, cryptosystems, and the Pohlig-Hellman conventional cryptosystem. Discover the contributions of unsung heroes in the field, including John Gill and Schroeppel. Learn about the rejection and subsequent acceptance of Merkle's groundbreaking paper, the creation of the RSA public key cryptosystem, and the Diffie-Hellman-Merkle public key distribution method. Gain insights into the political and technical challenges surrounding the classification of cryptographic research, and understand how these issues were ultimately resolved, culminating in a 1993 Congressional request for an NRC study on the matter.