Date: 2015/8/27

      Place: Collaboration Room #7 10:30 - 12:00

      Name: Ms. Elena Pagnin
          Chalmers University of Technology, Sweden

      Title 1: Homomorphic authentication in Linear Network Coding

      Authentication codes are important building block of many secure communication systems. In this talk, I will present homomorphic authentication codes (HACs in short), which represent an unconditional secure method to achieve message authentication in networks that employ linear-coding. The main feature of HACs is to be linear in the messages (homomorphic), thus HACs perfectly suit communication networks in which the nodes perform linear operation on the incoming data (e.g. linear network coding). The study of authentication codes in the linear network coding framework is motivated by the fact that, as a transmission method, linear coding provides higher throughput than the classical store and forward method.

      Title 2: On the Leakage of Information in Biometric Authentication

      In biometric authentication protocols, a user is authenticated or granted access to a service if her fresh biometric trait matches the reference biometric template stored on the service provider. This matching process is usually based on a suitable distance which measures thesimilarities between the two biometric templates. In this talk, we prove that, when the matching process is performed using a specific family of distances, then information about the reference template is leaked. We show how it is possible to perform a template recovery attack even in privacy-preserving biometric authentication protocols and we formalise this “leakage of information” in a mathematical framework.