Edge Cryptography and the Codevelopment of Computer Networks and Cybersecurity

The Private Line Interface was a cryptographic cybersecurity device used on the Arpanet, operating at the edge of the network with little modification of the network infrastructure. As a result of the historical trajectory furthered and illustrated by the PLI, significant cryptographic resources remain at the edges (or ends) of the networks that constitute the Internet today. This study is an entry into the historical relationship between cryptography and computer networks.