Actively Secure Dishonest Majority Table Join in The JOCONDE Project

Abstract.  The Eurostat JOCONDE project developed a specification and prototype of a shared multi-party computation system for official statistics. The purpose of the system is to enable national statistics offices to collaborate among each other and with industry partners on statistical analysis of confidential microdata. The system uses secure multi-party computation (MPC) and trusted execution environments (TEE) in tandem to provide strict data protection guerentees. In the strictest security configuration, the underlying MPC protocols must provide active security against two out of three computing parties.  In this talk, I will present the MPC protocols used for actively secure aggregation of tabular data in the JOCONDE prototype. We generalized the pseudorandom permutation based join protocol of Laur, Talviste, and Willemson (2013) to the active security dishonest majority setting. For the pseudorandom permutation, we developed a secure protocol based on the Poseidon2 hash function. The resulting protocols are used to join two tables with 1 million rows each in 4 hours and 10 minutes.

Joint work: Hendrik Eerikson, Sona Kravtšenko, Pille Pullonen-Raudvere

Suggested readings

• Eurostat JOCONDE project
• JOCONDE prototype (GitHub repository)