Zero-knowledge proof

A computer system, comprising:

• at least one computing device comprising memory comprising one or more memory units and a processing apparatus comprising one or more processing units, wherein the memory stores one or more portions of code arranged to run on the processing apparatus, wherein, when executed by the processing apparatus, the code causes the processing apparatus to define a series of nodes for generating a zero-knowledge proof for proving knowledge of a pre-image value, wherein each of the one or more portions of code corresponds to one or the nodes of the series of nodes, wherein each of the one or more portions of code, when executed, causes the processing apparatus to:
• obtain a respective next pre-image block of a series of pre-image blocks, wherein the series of pre-image blocks, when combined, form a pre-image value;
• obtain a respective current state and a respective current iteration counter;
• evaluate an instance of a predefined compression function, based on the respective current state, to compute a respective next state;
• increment the respective current iteration counter to generate a respective next iteration counter;
• determine, based on a respective next pre-image block of the series of pre-image blocks, that the predefined compression function instance has been evaluated correctly;
• and
• generate a proof, wherein the proof attests to the predefined compression function instance being evaluated correctly;
• wherein the proof generated by a final node of the series of nodes proves knowledge of the pre-image value.