Paper 2021/342

N-for-1 Auth: N-wise Decentralized Authentication via One Authentication

Weikeng Chen and Ryan Deng and Raluca Ada Popa

Abstract

Decentralizing trust is a prominent principle in the design of end-to-end encryption and cryptocurrency systems. A common issue in these applications is that users possess critical secrets, and users can lose precious data or assets if these secrets are lost. This issue remains a pain-point in the adoption of these systems. Existing approaches to solve this issue such as backing up user secrets through a centralized service or distributing them across N mutually distrusting servers to preserve decentralized trust are either introducing a central point of attack or face usability issues by requiring users to authenticate N times---once to each of the N servers. We present N-for-1 Auth, a system that enables a user to authenticate to N servers independently, with the work of only one authentication. N-for-1 Auth provides the same user experience in the distributed trust setting to the user experience in a typical centralized system.