SoK: Authenticated Prefix Relations -- A Unified Perspective On Relative Time-Stamping and Append-Only Logs

TL;DR

This paper unifies the concepts of relative timestamping and append-only logs through the authentication of prefix relations, introducing a comprehensive framework and evaluating existing schemes within this new perspective.

Contribution

It presents a unified theoretical framework for relative timestamping and append-only logs, introduces transitive prefix authentication graphs, and provides a comprehensive survey of existing schemes.

Findings

Derived complexity criteria for prefix authentication

Defined transitive prefix authentication graphs

Surveyed existing schemes within the new framework

Abstract

Secure relative timestamping and secure append-only logs are two historically mostly independent lines of research, which we show to be sides of the same coin -- the authentication of prefix relations. From this more general viewpoint, we derive several complexity criteria not yet considered in previous literature. We define transitive prefix authentication graphs, a graph class that captures all hash-based timestamping and log designs we know of. We survey existing schemes by expressing them as transitive prefix authentication graphs, which yields more compact definitions and more complete evaluations than in the existing literature.