Smart contract execution using distributed coordination
The invention relates to distributed ledger technologies such as consensus-based blockchains. Computer-implemented methods for smart contract outcome determination are described. The invention is implemented using a blockchain network, which may be, for example, a Bitcoin blockchain. A set of conditions is determined between counterparties, with the set of conditions having a plurality of possible outcomes that includes a first possible outcome associated with a first distribution of a digital asset and a second possible outcome associated with a second distribution, different from the first distribution, of the digital asset. A counterparty transaction is created that includes, as output, the set of conditions encoded into computer-executable instructions and the digital asset. An outcome is received from a third party, with the outcome corresponding to the first possible outcome or the second possible outcome. An outcome transaction is created to transfer control of the digital asset of the counterparty transaction, the outcome transaction including the outcome as input. As a result of validating the outcome transaction at a node in a blockchain network, the digital asset is distributed, based at least in part on the outcome, to the counterparties in accordance with the first possible outcome or the second possible outcome.
1. A computer-implemented method comprising:
determining a set of conditions between counterparties, the set of conditions having a plurality of possible outcomes that includes:
a first possible outcome associated with a first distribution of a digital asset; and
a second possible outcome associated with a second distribution, different from the first distribution, of the digital asset;
creating a counterparty transaction that includes, as output, the set of conditions encoded into computer-executable instructions and the digital asset;
receiving an outcome from a third party, the outcome corresponding to the first possible outcome or the second possible outcome;
creating an outcome transaction to transfer control of the digital asset of the counterparty transaction, the outcome transaction including the outcome as input; and
as a result of validating the outcome transaction at a node in a blockchain network distributing, based at least in part on the outcome, the digital asset to the counterparties in accordance with the first possible outcome or the second possible outcome;
the method further comprising:
receiving, from the third party, a plurality of outcome keys corresponding to the plurality of possible outcomes, wherein the outcome is a cryptographic key that corresponds to one of the plurality of outcome keys;
combining a secret value determined by the counterparties with each of the plurality of outcome keys to produce a plurality of obfuscated outcome keys;
creating the counterparty transaction to further include the plurality of obfuscated outcome keys; and
validating the outcome transaction includes:
combining the cryptographic key with the secret value to produce an outcome signing key for signing the outcome transaction; and
distributing the digital asset to the counterparties based at least in part on which of the plurality of obfuscated outcome keys is associated with the outcome signing key.
2. The computer-implemented method according to claim 1 , wherein the third party is a group comprising a plurality of members.
3. The computer-implemented method according to claim 2 , wherein the outcome is a result of a consensus of answers submitted by the plurality of members.
4. The computer-implemented method according to claim 2 , further comprising:
determining:
an amount of members to comprise the plurality of members; and
a threshold number to determine the outcome; and
the outcome matches answers submitted by at least the threshold number of the plurality of members.
5. The computer-implemented method according to claim 4 , wherein the outcome is determined based at least in part on key shares submitted by the plurality of members, the key shares determined according to a secret sharing scheme.
6. The computer-implemented method according to claim 5 , wherein the key shares are committed by the plurality of members to a block in a proof-of-stake blockchain.
7. The computer-implemented method according to claim 1 , further comprising:
creating at least one coordination algorithm transaction associated with a second digital asset; and
as a result of validating a fee transaction created to transfer control of the second digital asset, distributing the second digital asset to the third party.
8. The computer-implemented method according to claim 7 , wherein the second digital asset comprises a deposit portion contributed by the third party.
9. The computer-implemented method according to claim 7 , wherein the second digital asset comprises a fee portion contributed by the counterparties.
10. The computer-implemented method according to claim 9 , wherein:
the outcome is a result of a consensus of answers submitted by a plurality of members;
the plurality of members includes a member whose answer is a mismatch to the consensus; and
as a result of the answer being a mismatch to the consensus of answers, distributing of the second digital asset excludes the member from receiving the fee portion.
11. A system, comprising:
a processor; and
memory including executable instructions that, as a result of execution by the processor, causes the system to perform the computer-implemented method according to claim 1 .
12. A non-transitory computer-readable storage medium having stored thereon executable instructions that, as a result of being executed by a processor of a computer system, cause the computer system to at least perform the computer-implemented method according to claim 1 .
13. A system, comprising:
a processor; and
memory including executable instructions that, as a result of execution by the processor, causes the system to perform the computer-implemented method according to claim 2 .
14. A system, comprising:
a processor; and
memory including executable instructions that, as a result of execution by the processor, causes the system to perform the computer-implemented method according to claim 7 .
15. A non-transitory computer-readable storage medium having stored thereon executable instructions that, as a result of being executed by a processor of a computer system, cause the computer system to at least perform the computer-implemented method according to claim 2 .
16. A non-transitory computer-readable storage medium having stored thereon executable instructions that, as a result of being executed by a processor of a computer system, cause the computer system to at least perform the computer-implemented method according to claim 7 .
17. The computer-implemented method according to claim 1 , wherein one of the plurality of possible outcomes is associated with a timeout condition for the set of conditions, and further wherein the plurality of possible outcomes further includes a third possible outcome associated with a third distribution of the digital asset, different from the first and second distributions of the digital asset, the third possible outcome being associated with said timeout condition.
18. The computer-implemented method according to claim 1 , wherein the digital asset comprises a first amount of the digital asset contributed by a first party and a second amount of the digital asset contributed by a second party.
19. The computer-implemented method according to claim 18 , wherein:
one of the plurality of possible outcomes is associated with a timeout condition for the set of conditions; and
the method further comprises:
as a result of validating the outcome transaction and as a result of an occurrence of the timeout condition, refunding the first amount to the first party and the second amount to the second party.
20. The computer-implemented method according to claim 1 , wherein the digital asset comprises a first amount of the digital asset contributed by a first party and a second amount of the digital asset contributed by a second party.
21. The computer-implemented method according to claim 20 , wherein:
one of the plurality of possible outcomes is associated with a timeout condition for the set of conditions; and
the method further comprises:
as a result of validating the outcome transaction and as a result of an occurrence of the timeout condition, refunding the first amount to the first party and the second amount to the second party.