As of 2012, I’m a postdoctoral researcher in the Cryptography Group at the Courant Institute of Mathematical Sciences of the New York University. Before joining NYU I was a postdoc in the Crypto Team at the École Normale Supérieure in Paris.

I did my graduate studies at University of Catania where I earned my Ph.D. in Computer Science in March 2010. My advisor was Dario Catalano.
I also spent part of my PhD visiting Yevgeniy Dodis at NYU and Rosario Gennaro at IBM Research

AG 1, AG 2, AG 3, AG 4, AG 5, SWS, RG1, MMCI   Info

Expert Audience

English

60 Minutes

Saarbrücken

Digital signatures can be seen as the digital equivalent of handwritten signatures, and are considered one of the most important cryptographic primitives. At a high level, they allow a user Alice to authenticate a digital document by generating a piece of information, that is the signature, using a secret key which is known only by her. Any other user who gets a matching public verification key can check the validity of such signature and thus be convinced that it was generated by Alice. Digital signatures are required to satisfy the most natural security property one could expect: no one, except who knows the secret key, should be able to generate valid signatures.
In the quest of mimicking in the digital world what we are used to do in the real world, an interesting question naturally arises: can Alice delegate the signing process (on a restricted set of messages) to third parties without having to reveal to them her secret key?
A positive answer to this question has been recently given by Boneh et al. (PKC 2009) by means of homomorphic signatures.

In the first part of my talk, I will present the notion of homomorphic signatures: I will describe important applications which motivate the study of this primitive, and I will survey recent results of mine that propose efficient constructions.

In the second part of the talk I will move the focus to a related, but more general and intriguing question: can we sign computation? Are there means to certify that a program has been run correctly and/or on the correct inputs? These and similar questions are nowadays arising in the context of cloud computing applications in which users want to delegate computation and memory to third parties that are called cloud providers. I will describe relevant security issues emerging from these applications, and will discuss how cryptography can help to solve such problems.

During my presentation I will also mention the usual approaches underlying the process of designing cryptographic protocols, with a particular emphasis on how theory and practice can interact in a significant way.

The talk is mainly based on the following works joint with Dario Catalano, Rosario Gennaro and Bogdan Warinschi.
- D. Catalano, D. Fiore and B. Warinschi. Adaptive Pseudo-Free Groups and Applications. EUROCRYPT 2011
- D. Catalano, D. Fiore and B. Warinschi. Efficient Network Coding Signatures in the Standard Model. PKC 2012
- D. Fiore and R. Gennaro. Publicly Verifiable Delegation of Large Polynomials and Matrix Computations, with Applications. Pre-print (May 2012): http://eprint.iacr.org/2012/281

Brigitta Hansen

0681 93039102

--email hidden

passcode not visible

logged in users only