“Private Smart Contracts on the Blockchain: Challenges and New Advances”

Location: LTS Auditorium, 8080 Greenmead Drive

Speaker:
Charalampos (Babis) Papamanthou
Assistant professor, Department of Electrical and Computer Engineering and UMIACS

Abstract:
Decentralized cryptocurrencies (e.g., Bitcoin) promise to revolutionize financial industries, forever changing the way money is transferred. They support simple monetary transactions between users without trusting a central authority (e.g., a government or a bank).

Smart contracts (e.g., Ethereum) are an extension of the above idea, facilitating the expression of more complex rules for governing the flow of money (instead of just the basic rule that Alice transfers x units of money to Bob if Alice’s account has a balance of at least x). To that end, smart contracts support a Turing-complete transaction language capable of describing arbitrary and complex financial transactions such as auctions, pay-as-you-go rental agreements, and lotteries. However, due to the public nature of the decentralized data structure enabling the above technology (the blockchain), many privacy concerns have emerged.

In this talk I will present our system Hawk, a proposal for privacy-preserving smart contracts that uses zero-knowledge proofs. Then I will highlight several of its limitations and I will present our current work on new zero-knowledge proofs that can lead to better solutions in terms of security and practicality.

Speaker Bio:
Charalampos (Babis) Papamanthou is an assistant professor in the Department of Electrical and Computer Engineering (ECE) at UMD.

He is also affiliated with the Institute for Advanced Computer Studies, where he is a member of the Maryland Cybersecurity Center.

Papamanthou works on applied cryptography and computer security, especially on technologies, systems and theory for secure and private cloud computing.

At UMD, Papamanthou has received the NSF CAREER award, Google Faculty Research Award, the Yahoo! Faculty Research Engagement Award, the NetApp Faculty Fellowship, the 2013 UMD Invention of the Year Award, the 2014 Jimmy Lin Award for Invention, and the George Corcoran Award for Excellence in Teaching.

His research is currently funded by federal agencies (NSF, NIST and NSA) and industry (Google, Yahoo!, NetApp and Amazon).

Papamanthou received his doctorate in computer science from Brown University.