Fine-Grained Secure Computation.

This paper initiates a study of Fine Grained Secure Computation: i.e. the construction of secure computation primitives against “moderately complex” adversaries. We present definitions and constructions for compact Fully Homomorphic Encryption and Verifiable Computation secure against (non-uniform) 𝖭𝖢^1 adversaries. Our results do not require the existence of one-way functions and hold under a widely believed separation assumption, namely 𝖭𝖢^1⊊⊕𝖫/ 𝗉𝗈𝗅𝗒 . We also present two application scenarios for our model: (i) hardware chips that prove their own correctness, and (ii) protocols against rational adversaries potentially relevant to the Verifier’s Dilemma in smart-contracts transactions such as Ethereum.