Christopher Newton

Dr Christopher J P Newton

Research Fellow

Academic and research departments

Surrey Centre for Cyber Security.

My publications


Wesemeyer Steve, Newton Christopher, Treharne Helen, Chen Liqun, Sasse Ralf, Whitefield Jordan (2019) Formal Analysis and Implementation of a TPM 2.0-based
Direct Anonymous Attestation Scheme,
15th ACM ASIA Conference on Computer and Communications Security
Direct Anonymous Attestation (Daa) is a set of cryptographic
schemes used to create anonymous digital signatures. To provide additional assurance, Daa schemes can utilise a Trusted Platform Module (Tpm) that is a tamper-resistant hardware device embedded in a computing platform and which provides cryptographic primitives
and secure storage. We extend Chen and Li?s Daa scheme to
support: 1) signing a message anonymously, 2) self-certifying Tpm keys, and 3) ascertaining a platform?s state as recorded by the Tpm?s platform configuration registers (PCR) for remote attestation, with
explicit reference to Tpm 2.0 API calls.We perform a formal analysis of the scheme and are the first symbolic models to explicitly include the low-level Tpm call details. Our analysis reveals that a fix proposed
by Whitefield et al. to address an authentication attack on an Ecc-Daa scheme is also required by our scheme. Developing a finegrained,
formal model of a Daa scheme contributes to the growing
body of work demonstrating the use of formal tools in supporting
security analyses of cryptographic protocols. We additionally provide
and benchmark an open-source C++ implementation of this
Daa scheme supporting both a hardware and a software Tpm and
measure its performance.