Abstract: A system and a method are disclosed for receiving, by a processor, a request from a client device, and, in response to receiving the request, transmitting a machine learning model and training data to the client device. The processor receives a trained version of the machine learning model, where a nonce is generated as a byproduct of the trained version, the nonce being at least a part of a candidate value for a new block being added to a blockchain. In response to receiving the trained version, the processor determines whether the trained version of the machine learning model satisfies an acceptance criterion. In response to determining that the trained version of the machine learning model satisfies the acceptance criterion, the processor causes release of a token to a user of the client device.