Paper 2018/401

L-DAA: Lattice-Based Direct Anonymous Attestation

Nada EL Kassem and Liqun Chen and Rachid El Bansarkhani and Ali El Kaafarani and Jan Camenisch and Patrick Hough

Abstract

Direct Anonymous Attestation (DAA) is an anonymous digital signature that aims to provide both signer authentication and privacy. DAA was designed for the attestation service of the Trusted Platform Module (TPM). In this application, a DAA signer role is divided into two parts: the principal signer which is a TPM, and an assistant signer which is a standard computing platform in which the TPM is embedded, called the Host. A design feature of a DAA solution is to make the TPM workload as low as possible. This paper presents a lattice-based DAA (L-DAA) scheme to meet this requirement. Security of this scheme is proved in the Universally Composable (UC) security model under the hard assumptions of the Ring Inhomogeneous Short Integer Solution (Ring-ISIS) and Ring Learning With Errors (Ring-LWE) problems. Our L-DAA scheme includes two building blocks, one is a modification of the Boyen lattice based signature scheme and another is a modification of the Baum et al. lattice based commitment scheme. These two building blocks may be of independent interest.