Bitcoin is the first digital currency to see widespread adoption. While payments are conducted between pseudonyms, Bitcoin cannot offer strong privacy guarantees: payment transactions are recorded in a public decentralized ledger, from which much information can be deduced. In this talk I will discuss two new proposals to add privacy to Bitcoin. The first, called Zerocoin, tackles these problems by unlinking transactions from the payment’s origin. Yet, it still reveals payments’ destinations and amounts, and is limited in functionality. In the second approach Idescribe a full-fledged ledger-based digital currency with strong privacy guarantees. These results leverage recent advances in zero-knowledge Succinct Non-interactive ARguments of Knowledge (zk-SNARKs). Finally, I describe how these results can be used to construct advanced primitives such as decentralized anonymous credentials, which permit new privacy applications for decentralized systems.
Speaker Biography
Prof. Matthew Green is a Research Professor at the Johns Hopkins University Information Security Institute. His research focus is on cryptographic techniques for maintaining users’ privacy, and on technologies that enable the deployment of privacy-preserving protocols. From 2004-2011, Green served as CTO of Independent Security Evaluators, a custom security evaluation firm with a global client base. Along with a team at Johns Hopkins and RSA Laboratories, he discovered flaws in the Texas Instruments Digital Signature Transponder, a cryptographically-enabled RFID device used in the Exxon Speedpass payment system and in millions of vehicle immobilizers.