CWI Cryptology Group

Abstract: In this talk, we review the early days of Interactive Proofs, Interactive Arguments and other Zero-Knowledge protocols. We highlight Chaum’s contributions to this young (30 years ago) field and where it led us today. We survey current research on Argument Systems, as well as Zero-Knowledge proofs where soundness and zero-knowledge only rest on the assumption that no information can travel faster than the speed of light.

Abstract: Multiparty computation (MPC) provides cryptographic means that enable mutually distrustful parties to collaborate in a secure way, ensuring that individual data used for the collaboration remains private. The theoretical foundations of MPC were set in the early eighties in a sequence of pioneering work that showed general possibility results. Since then, MPC has remained a lively research topic but was long considered to be of theoretical interest only due to its large computational overhead. However, thanks to the continuous efforts in making MPC more efficient, it is now at the verge of being practically relevant and is gradually starting to experience real world deployment. In this presentation, I explain the general goal of MPC, give some details on how it can be achieved, and discuss some potential and actual real-world applications.

Abstract: Although practised as an art and science for ages, cryptography had to wait until the mid-twentieth century before Claude Shannon gave it a strong mathematical foundation. However, Shannon's approach was rooted in his own information theory, itself inspired by the classical physics of Newton and Einstein. When quantum theory is taken into account, new vistas open up both for codemakers and codebreakers. Is this a blessing or a curse for the protection of privacy and the fight against Big Brother so central to David's mission? As we shall see, the jury is still out! (No prior knowledge in quantum theory will be assumed)

Abstract: In 1984, David Chaum wrote: "Today, individuals provide substantially the same identifying information to each organization with which they have a relationship. In a new [better] paradigm, individuals [should] provide different "pseudonyms" or alternate names to each organization. A critical advantage of systems based on such pseudonyms is that the information associated with each pseudonym can be insufficient to allow data on an individual to be linked and collected together, and thus they can prevent the formation of a dossier society reminiscent of Orwell's "1984"." Thirty five years later, this vision is as relevant as ever. Luckily, we also have as many years of developments of cryptographic approaches to the 1984 problem. In this talk, I will go over these approaches, from anonymous credentials, to anonymous electronic cash and untraceable e-tokens, to anonymous attestation, and beyond.

Abstract: TBA