PUF Crypto-block Konstantinos Goutsos EEE8097: Individual Project School of Electrical and Electronic Engineering Newcastle University March 2015 - Newcastle Upon Tyne, UK 1 

Physically Unclonable Functions (PUFs) Physical: Quantifying minor hardware variations Unclonable: Variations cannot be measured or controlled Exploit these defects to produce unique responses March 2015 - Newcastle Upon Tyne, UK 2 

PUF Model PUF Measurement Error Correction Response Hash Function Unique Output Challenge March 2015 - Newcastle Upon Tyne, UK 3 

PUF Taxonomy Delay based March 2015 - Newcastle Upon Tyne, UK 4 PUFs Memory based Butterfly Latch SRAM Flip-flop Scan Path Arbiter Ring Oscillator 

SRAM PUFs (1) March 2015 - Newcastle Upon Tyne, UK 5 (Holcomb 2009) 

SRAM PUFs (2) March 2015 - Newcastle Upon Tyne, UK 6 (Holcomb 2009) 

Attacks against PUFs →Invasive attacks: Believed to be infeasible →Offline attacks: Cannot be applied →Modelling attacks: Use a number of challenge/response pairs model the PUF (Rührmair 2010) March 2015 - Newcastle Upon Tyne, UK 7 

Technical Aims o Create a PUF data signature system prototype o Design a source device verification scheme using a 3rd party device (while keeping the PUF details private) March 2015 - Newcastle Upon Tyne, UK 8 

PUF Crypto-block: Motivation Growing need for source identification of digital data Security issues increasingly important (i.e. Internet of Things) Copyright and other legal issues Privacy protection is imperative March 2015 - Newcastle Upon Tyne, UK 9 

Possible Applications →Wireless Sensor Networks, Internet of Things →Intellectual Property protection →Enhanced security protocols (i.e. using SmartCards) March 2015 - Newcastle Upon Tyne, UK 10 

Objectives (1)  Design and develop a PUF-based signature generation system March 2015 - Newcastle Upon Tyne, UK 11 SRAM Measurement Error Correction Hash Function Signature FPGA/Software Signing Data 

Objectives (2)  Build a prototype and acquire metrics  Evaluate system correctness, performance and security March 2015 - Newcastle Upon Tyne, UK 12 

Objectives (3) March 2015 - Newcastle Upon Tyne, UK 13 Signature Block Data Signature Data PUF Key Verification Block Result Data Signature Source Device Verification third-party  Develop a signature scheme aided by the PUF and a third-party verifier Signature Block Data Signature Data PUF Key Verification Block Result Data Signature Source Device Verification third-party 

PUF Crypto-block A system for PUF-aided data signing without leaking any information about the PUF. Thank you for your attention. March 2015 - Newcastle Upon Tyne, UK 16 

References C. Herder, M. D. Yu, F. Koushanfar, and S. Devadas, “Physical unclonable functions and applications: A tutorial,” Proceedings of the IEEE, vol. 102, no. 8. pp. 1126–1141, 2014. D. E. Holcomb, W. P. Burleson, and K. Fu, “Power-Up SRAM state as an identifying fingerprint and source of true random numbers,” IEEE Trans. Comput., vol. 58, pp. 1198– 1210, 2009. U. Rührmair, F. Sehnke, J. S ölter, G. Dror, S. Devadas, and J. Ü. Schmidhuber, “Modeling attacks on physical unclonable functions,” Proc. 17th ACM Conf. Comput. Commun. Secur. - CCS ’10, p. 237, 2010. March 2015 - Newcastle Upon Tyne, UK 17