Random access machine in secure multi-party computation

Graduation date: 2016Secure multi-party computation (MPC) is a conceptual framework in cryptography. It allows distrusting parties engage in a protocol to perform a computational task while still maintain some secure properties. Most existing approaches are required to interpret functions as a boolean circuit. With the recent state-of-art circuit garbling scheme, the performance are significantly improved. However, boolean circuit still has its limitations in practical usage, especially when the input data size is enormous.\ud In this thesis, we focus on another technique in MPC which is called random-access machines (RAM program). We first describe a zero-knowledge proof system in which a prover holds a large dataset M and can repeatedly prove NP relations about that dataset. This system achieves sublinear amortized cost. Second, we present the first practical protocols for evaluating RAM programs with security against malicious adversaries. The extra overhead of obtaining malicious security for RAM programs is minimal and does not grow with the running time of the program