Mutually Private Verifiable Machine Learning As-a-service: A Distributed Approach

Reliability is a crucial component to machine-learning-as-a-service platforms, as more and more critical applications depend on them. Thus, mechanisms employed to assure the integrity of computations performed on such platforms are pivotal to their robust functioning. Moreover, privacy protection, and performance guarantee at scale, are other major challenges surrounding these platforms that are by no means straightforward to overcome at the same time. In this paper, we have proposed a novel distributed approach, which uses specialized composable proof systems at its core, to respond to these challenges. At a high level, we adopt a divide-and-conquer approach to build efficient proof systems for machine-learning-based services in order to ensure the correctness of results. More precisely, the mathematical formulation of the machine learning task is divided into multiple parts, each of which is handled by a different specialized proof system; these proof systems are then combined with the commit-and-prove methodology to guarantee correctness as a whole. With privacy safeguards built into the design, our approach also assures that neither user data nor model parameters, which constitute the intellectual property of service providers are exposed in the process. We have showcased the usability of our approach within a machine learning service provider that offers classification services through a linear support vector machine (SVM) model. Our complexity analysis indicates that our system could be used in practical settings.