| Title | : | Privacy-Preserving Cryptography from Pairings and Lattices |
| Speaker | : | Fabrice Mouhartem (ENS Lyon, France) |
| Details | : | Fri, 3 Aug, 2018 3:30 PM @ A M Turing Hall |
| Abstract: | : | As the amount of data exchanged through the internet is growing, protecting users' data has become a major concern (as attests the recent application of the GDPR law in Europe). Fortunately, cryptography provided many different primitives to address these problems, such as anonymous credentials, e-cash or group signatures. However, some of these constructions suffers from drawbacks, such as being quantum-vulnerable, or relying on security assumptions that we don't understand well. Therefore, the study and concrete realizations of these primitives become crucial. In the context of privacy-preserving cryptography, a fundamental building block are zero-knowledge proofs. To put it short, it consists of an interactive protocol between a prover and a verifier, where the prover tries to convince the verifier of the validity of a statement without leaking further information than its validity. This talk will thus focus on zero-knowledge proofs and their applications in privacy-preserving cryptography. To this aim, we will present in more details a construction of group encryption from simple lattice assumptions that has been made possible from these improvements. Group encryption is a primitive allowing sender to send an encrypted message anonymously to a user who formerly registered to a group (i.e., a set of users), while proving that the message satisfies additional properties. This ensures the receiver's privacy, while attesting that the message is intended to an authorized user. This primitive has applications in firewall filtering, anonymous cloud storage service or anonymous trusted third parties. Other primitives will also be discussed, such as group signatures and adaptive oblivious transfer. |
