Blockchain-based crowdsourcing

1. A system, comprising:

a distributed ledger stored on physical peer-to-peer network nodes having a smart contract related to a problem statement, the smart contract enabling a zero-knowledge proof concerning the problem statement,

wherein the zero-knowledge proof is based on a validation function which takes a putative solution and returns a score that represents the quality of the putative solution,

wherein the smart contract defines a function which is configured to be called on smart contract creation by a Requestor, wherein the function is configured to record a timestamp after which no further solutions will be accepted by smart contract and before which Requestor cannot withdraw a bounty.

2. The system of claim 1 , wherein the distributed ledger is configured to receive a putative solution to a problem statement, and to verify the putative solution to the problem statement using the zero-knowledge proof.

3. The system of claim 1 , wherein the zero-knowledge proof is generated based on a computation object which is based on the validation function.

4. The system of claim 1 , wherein the zero-knowledge proof is implemented using a zkSNARK scheme.

5. The system of claim 1 , wherein the distributed ledger is implemented as a blockchain.

6. The system of claim 1 , wherein the zero-knowledge proof defines a function configured to verify a proof of solution.

7. The system of claim 1 , wherein the zero-knowledge proof defines a function configured to build a proof of solution according to the zero-knowledge proof.

8. The system of claim 1 ,

wherein the smart contract defines a function which is configured to be called only by a Requestor, and only after the deadline set by the initialize function has passed and no valid solution has been submitted.

9. The system of claim 1 , wherein the smart contract defines a function which is configured to accept a proof of solution.

10. The system of claim 9 , wherein the function is configured to timestamp the received proof of solution in order to record the time and date of receipt of the proof of solution.

11. The system of claim 1 wherein the smart contract defines a function which is configured to accept an encrypted solution as payload.

12. The system of claim 11 , wherein the function is configured to run a verifier function against a proof of solution, and wherein the function is configured to, if the verification result is positive, automatically transfer a bounty to the address of the function-caller, and to provide an encrypted solution to Requestor.

13. The system of claim 1 wherein the distributed ledger is configured to manage a bounty related to the problem statement or wherein the distributed ledger is configured to manage a bounty in the form of cryptocurrency.

14. The system of claim 1 , wherein the smart contract defines

a function configured to provide a proof-generating software to Solvers; or

a function configured to provide an auxiliary application to Solvers which is configured to help a Solver to find an optimal solution to the problem statement; or

a function configured to provide auxiliary data available from the smart contract, such as the problem statement Z, a Requestor's public key, a proving key, and/or functionality to build a proof.

15. The system of claim 1 , further comprising a distributed file system for storing a solution to the problem statement.

16. The system of claim 1 , wherein the smart contract defines

a function which accepts an amount and date; and/or

a function which accepts a bounty amount, a duration of validity, a public key, and a set of public inputs for a zero-knowledge proof; and/or

a function which accepts status information and which returns a list of bounties filtered on their status information; and/or

a function which deactivates the function for submitting a bounty.

17. A computer-implemented method, comprising:

storing, by a distributed ledger. a smart contract related to a problem statement;

requesting, by a Requestor, solutions to the problem statements; and

verifying, by the distributed ledger a putative solution to the problem statement provided by a Solver using a zero-knowledge proof,

wherein the zero-knowledge proof is based on a validation function which takes a putative solution and returns a score that represents the quality of the putative solution; and

defining, by the smart contract, a function which is configured to be called on smart contract creation by a Requestor, wherein the function is configured to record a timestamp after which no further solutions will be accepted by the smart contract and before which Requestor cannot withdraw a bounty.

18. An electronic device comprising circuitry configured to implement a zero knowledge scheme in a smart contract and to store the smart contract on a distributed ledger,

wherein the smart contract enables a zero-knowledge proof concerning the problem statement, wherein the zero-knowledge proof is based on a validation function which takes a putative solution and returns a score that represents the quality of the putative solution,

wherein the smart contract defines a function which is configured to be called on smart contract creation by a Requestor, wherein the function is configured to record a timestamp after which no further solutions will be accepted by the smart contract and before which Requestor cannot withdraw a bounty.

19. An electronic device comprising circuitry configured to create a proof of solution from a solution to a problem statement using a zeroknowledge proof implemented in a smart contract stored on a distributed ledger,

wherein the zero-knowledge proof is based on a validation function which takes a putative solution and returns a score that represents the quality of the putative solution,

wherein the smart contract defines a function which is configured to be called on smart contract creation by a Requestor, wherein the function is configured to record a timestamp after which no further solutions will be accepted by the smart contract and before which Requestor cannot withdraw a bounty.