InterTrust's patents turned out to be worth more than its products. Victor Shear started the company in 1990 to solve a problem most people had not noticed yet: once a song or a book is digital, anyone can copy it for free. InterTrust built a system to wrap content in a secure container with rules about who could open it and what they owed. When it went public in October 1999, Napster was months old and the record labels were scared.

A Container With Rules

Shear's idea was called digital rights management, or DRM. InterTrust's DigiBox container held a file along with instructions for its use. A buyer might get to play a song three times, or read a report but not print it. Payment ran through the same system. InterTrust spent most of the 1990s writing software and filing patents on these ideas, long before it had many paying customers.

Patents Worth a Fortune

InterTrust sold shares at $18 on October 27, 1999, and listed on Nasdaq as ITRU. The stock soared during the bubble and then collapsed. Its software never caught on widely. Its patents did matter, and in 2001 InterTrust sued Microsoft over them. In January 2003 Sony and Philips bought InterTrust for about $453 million. In 2004 Microsoft settled the patent case for $440 million.

Cover: Saints Augustine and Peter, Paolo Veneziano. Art Institute of Chicago, public domain. Chosen for Saint Peter with his keys (who holds access).