a new model for estimating bit error probabilities of ring-oscillator
TRANSCRIPT
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Matthias Hiller, Georg Sigl and Michael Pehl
A New Model for Estimating Bit Error gProbabilities of Ring-Oscillator PUFs
11/07/2013
8th International Workshop on Reconfigurable Communication-centric Systems-on-Chip
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Outline
• Introduction to PUFsIntroduction to PUFs
• New Modeling TechniqueNew Modeling Technique• Empirical Results
• Conclusions
11/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC 2
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Introduction
Embedded securityM t t i
Secure key storagePrerequisite for
Measurement, storage, processing,transmission of sensitive data
Non-volatile memorySecure but expensive
Prerequisite forcryptography
Secure, but expensiveTechnology andcost constraints
Solution: Physical Unclonable Functions
311/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Physical Unclonable Functions
• Measurement of internal physical properties
• Randomness
• Precise PUF models necessary for error correction
411/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Ring Oscillators from Logic Gates
1t 2t 3t 4t 5t1f
5
1iit
f
511/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Ring Oscillator PUF
fi
fj
Suh et al., 2007
611/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
,
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Bit derivation
711/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Randomness
Uniqueness ReliabilityU que ess e ab ty
811/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
State of the art
• Direct comparison offrequenciesq
• Problem: PrecisionProblem: Precision scales linearly with theeffort
e.g. Maiti et al. (HOST 2010), Armknecht et al (S&P 2011)Armknecht et al. (S&P 2011)
911/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Outline
• Introduction to PUFsIntroduction to PUFs
• New Modeling TechniqueNew Modeling Technique• Empirical Results
• Conclusions
11/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC 10
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Multivariate Distributionpdf f fpdf fi ,fj
fjfi
1111/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Reliability Analysis
1211/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Outline
• Introduction to PUFsIntroduction to PUFs
• New Modeling TechniqueNew Modeling Technique• Empirical Results
• Conclusions
11/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC 13
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Empirical Data
• Large scale case study at Virginia Tech in 2009Large scale case study at Virginia Tech in 2009
• Xilinx Spartan 3Xilinx Spartan 3
• 193 FPGAs• 193 FPGAs• 512 ROs per FPGA• 100 measurements per RO• 100 measurements per RO
http://rijndael ece vt edu/pufhttp://rijndael.ece.vt.edu/puf1411/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Frequency Distribution on FPGAs
1511/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Bit Error Probabilities with new ModelMeasurableMeasurable
Area
1611/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Validation of the Model
1711/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Conclusions
• Starting point: – Unknown bit error probability distributionp y
• New Model:– Correlated random variables– Estimation of entire bit error probability distribution
• Generalization:– Differential evaluation of physical measures for other PUF types
(Voltage, Time, Resistance, Capacitance, …)
1811/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Lessons learned
• PUF measurements can be correlated, probably evenunder constant environmental conditions
• Theoretically founded demonstration that differential ystructures are useful
• RO PUF is a very reliable PUF
• New model as one step towards certification
1911/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC
Technische Universität MünchenMatthias HillerInstitute for Security in Information Technology
Q ti ?Questions?
11/07/2013 - A New Model for Estimating Bit Error Probabilities of Ring-Oscillator PUFs - ReCoSoC 20