Abstract: An artificial intelligence model marketplace system secures both models and user data by managing computation-preserving-cryptography (CPC) encryption of data and models with public and private CPC user key pairs. Models can be encrypted by the marketplace system, model vendors, or third parties. e.g., in response to user requests to apply a model to their data to obtain a model prediction. Similarly, execution of the CPC encrypted models on CPC encrypted user data can be performed by the marketplace system, model vendors, or third parties. Selection of third parties for encryption and/or model execution work can be organized via staking mechanisms to create a secure, distributed, competitive marketplace for computational services.