We propose, formalize, and explore a cryptographic primitive called a {\em Sealed-Glass Proof (SGP)} that captures computation possible in an isolated execution environment with *unbounded leakage*, and thus in the face of arbitrarily powerful side-channel attacks. A SGP specifically models the capabilities of trusted hardware that can attest to *correct execution* of a piece of code, but whose execution is *transparent*, meaning that an application's secrets and state are visible to other processes on the same host.
Despite this strong threat model, we show that a SGP can support a range of practical applications. Our key observation is that a SGP permits safe verifiable computing in zero-knowledge, as information leakage results only in the prover learning her own secrets. Among other applications, we describe the implementation of an end-to-end bug bounty (or zero-day solicitation) platform that couples a SGX-based SGP with a smart contract. This platform enables a marketplace that achieves fair exchange, protects against unfair bounty withdrawals, and resists denial-of-service attacks by dishonest sellers. We also consider a slight relaxation of the SGP model that permits black-box modules instantiating minimal, side-channel resistant primitives, yielding a still broader range of applications. Our work shows how trusted hardware systems such as SGX can support trustworthy applications even in the presence of side channels.
Category / Keywords: cryptographic protocols / zero knowledge, trusted hardware, cryptocurrency, smart contracts Date: received 19 Jun 2016, last revised 20 Jun 2017 Contact author: florian tramer at gmail com Available format(s): PDF | BibTeX Citation Note: Full version with proofs. Version: 20170620:151613 (All versions of this report) Short URL: ia.cr/2016/635