  The integration of machine learning with blockchain technology has witnessed
increasing interest, driven by the vision of decentralized, secure, and
transparent AI services. In this context, we introduce opML (Optimistic Machine
Learning on chain), an innovative approach that empowers blockchain systems to
conduct AI model inference. opML lies a interactive fraud proof protocol,
reminiscent of the optimistic rollup systems. This mechanism ensures
decentralized and verifiable consensus for ML services, enhancing trust and
transparency. Unlike zkML (Zero-Knowledge Machine Learning), opML offers
cost-efficient and highly efficient ML services, with minimal participation
requirements. Remarkably, opML enables the execution of extensive language
models, such as 7B-LLaMA, on standard PCs without GPUs, significantly expanding
accessibility. By combining the capabilities of blockchain and AI through opML,
we embark on a transformative journey toward accessible, secure, and efficient
on-chain machine learning.
