How and Why More Secure Technologies Succeed in Legacy Markets: Lessons from the Success of SSH

Abstract

Secure shell (SSH) can safely be called one of the rare successes in which a more secure technology has largely replaced a less secure but entrenched tool: telnet. We perform a market analysis to determine how and why SSH succeeded despite the existence of an entrenched legacy tool while similar technologies such as secure file transfer protocols have been far less successful. We show that network externalities, usually a first order effect, were not a significant factor impeding the adoption of SSH, and that SSH offered equivalent functionality and greater ease of use. We argue that these factors were the primary consideration in the willingness to change. Additionally, we argue that the openness of the standard, which facilitated the creation of numerous compatible implementations, was a key element in the economic decision made by system administrators.