The Ring of Gyges: Investigating the Future of Criminal Smart Contracts
Ari Juels


Thanks to their anonymity (pseudonymity) and lack of trusted intermediaries, cryptocurrencies such as Bitcoin have created or stimulated growth in many businesses and communities, some of them regrettably criminal. Next-generation decentralized cryptocurrencies such as Ethereum will include rich scripting languages in support of smart contracts, general-purpose programs that autonomously intermediate transactions. We show how such smart contracts will enlarge the range of criminal activities that can exploit the pseudonymity and minimal trust assumptions of cryptocurrencies. We demonstrate the feasibility in the near future of criminal smart contracts (CSCs) for leakage of confidential information, theft of cryptographic keys, and various real-world crimes (murder, arson, terrorism). Our results highlight the urgency of creating policy and technical safeguards against CSCs in order to realize the considerable promise of smart contracts for beneficial goa! ls.

This talk will also include a brief overview of the many research projects at the Initiative for CryptoCurrencies and Contracts (IC3) at Cornell, Cornell Tech, and UC Berkeley. ( for information.)

Joint work with Ahmed Kosba (UMD) and Elaine Shi (Cornell Univ.)

Short Bio: Ari Juels is a Professor at the Jacobs Technion-Cornell Institute at Cornell Tech in New York City and a co-director of the Initiative for CryptoCurrencies and Contracts (IC3). To learn more, visit or