Studying Potential Side Channel Leakages on an Embedded Biometric Comparison System

We study in this work the potential side channel leakages of a hardware biometric comparison system that has been designed for fingerprints. An embedded biometric system for comparison aims at comparing a stored biometric data with a freshly acquired one without the need to send the stored biometric data outside the system. Here one may try to retrieve the stored data via side channel, similarly as for embedded cryptographic modules where one may try to exploit side channel for attacking the modules. On one hand, we show that we can find partial information by the means of simple Side Channel Analysis that may help to retrieve the stored fingerprint. On the other hand, we illustrate that reconstructing the fingerprint remains not trivial and we give some simple countermeasures to protect further the comparison algorithm.