Judge, Jury & Encryptioner: Exceptional Device Access with a Social Cost (1912.05620v3)

Abstract: We present Judge, Jury and Encryptioner (JJE) an exceptional access scheme for unlocking devices that does not give unilateral power to any single authority. JJE achieves this by placing final approval to unlock a device in the hands of peer devices. JJE distributes maintenance of the protocol across a network of "custodians" such as courts, government agencies, civil rights watchdogs, and academic institutions. Unlock requests, however, can only be approved by a randomly selected set of recently active peer devices that must be physically located by law enforcement in order to gain access to the locked device. This requires that law enforcement expend both human and monetary resources and pay a "social cost" in order to find and request the participation of random device owners in the unlock process. Compared to other proposed exceptional access schemes, we believe that JJE mitigates the risk of mass surveillance, law enforcement abuse, and vulnerability to unlawful attackers. While we propose a concrete construction, our primary goal with JJE is to spur discussion on ethical exceptional access schemes that balance privacy of individuals and the desires for law enforcement. JJE transparently reveals the use of exceptional access to the public and enforces a fixed social cost that, we believe, can be an effective deterrent to mass surveillance and abuse.