There’s a new paper from Microsoft Research, on a firmware-based TPM implementation (fTPM):
https://twitter.com/h0x0d/status/662465826503524352
This paper presents the design and implementation of a firmware-based TPM 2.0 (fTPM) leveraging ARM TrustZone. The fTPM is the reference implementation used in millions of mobile devices, and was the first hardware or software implementation to support the newly released TPM 2.0 specification. This paper describes the shortcomings of ARM’s TrustZone for implementing secure service (such as our implementation), and presents three different approaches to overcome them. Additionally, the paper analyzes the fTPM’s security guarantees and demonstrates that many of the ARM TrustZone’s shortcomings remain present in future trusted hardware, such as Intel’s Software Guard Extensions (SGX).
Authors: Himanshu Raj, Stefan Saroiu, Alec Wolman, Ronald Aigner, Jeremiah Cox, Paul England, Chris Fenner, Kinshuman Kinshumann, Jork Loeser, Dennis Mattoon, Magnus Nystrom, David Robinson, Rob Spiger, Stefan Thom, and David Wooten
http://research.microsoft.com/apps/pubs/default.aspx?id=258236
Firmware Security 