The Key Theory: Authenticating Decrypted Information in Litigation While Protecting Sensitive Sources and Methods

Since at least the beginning of the Cold War, the US government has grappled with the difficulty of introducing deciphered encrypted information in litigation without exposing sensitive sources and methods. This Article describes a method for cutting that Gordian knot. Encryption has been used since ancient times by militaries, spies, and others to communicate information covertly. As encryption technology has evolved in complexity and decreased in expense with the advent of computer encryption, it has created new opportunities for foreign powers, foreign and corporate spies, terrorist groups, and criminals. This Article articulates a "Key Theory" method for introducing evidence derived from encrypted information while protecting the US government's sources and methods. This Article articulates a theory to introduce evidence derived from encrypted information where the government has made the judgment to reveal that it can decrypt that information. The Key Theory can be used both to protect national security and promote a more efficient litigation process.