Privacy-preserving decentralized multi-party netting

A system for a multi-lateral netting between parties, the system comprising:

• a plurality of nodes, wherein each node related to a party of the parties, comprises a memory for storing program instructions, and a processor which, when executing the program instruction, is configured to:
• collect independently pending transactions between at least a part of the parties;
• publish a commitment of a party-dependent total value of the pending transactions to a bulletin board, wherein the bulletin board is accessible by all the parties;
• secretly share de-commitments among the parties, wherein each party-dependent de-commitment enables a verification to the party-dependent total value of the pending transactions as part of the commitment;
• compute, using a multi-party computation protocol, a revised balance after the multi-lateral netting in a process configured to handle the pending transactions;
• publish a determined liquidity status to the bulletin board;
• upon a determination of a failure in the publishing of the determined liquidity status, perform, using a subset of the plurality of nodes, a secure fault-tolerant multi-party computation by a determination of whether all the pending transactions, regardless of an order of the pending transactions, are settable maintaining positive liquidity for each party of the parties;
• upon a determination of a failure in the determination of whether all the pending transactions are nettable, determine an optimized subset of transactions that are nettable without violation of liquidity requirements for each party of the parties via a Karmarkar algorithm;
• and
• determine a secret share and a commitment of a new balance for each party of the parties.

A computer program product for a multi-lateral netting between parties, said computer program product comprising a computer readable storage medium having program instructions embodied therewith, said program instructions being executable by one or more computing systems to cause said one or more computing systems to:

• collect independently pending transactions between at least a part of the parties;
• publish a commitment of a party-dependent total value of the pending transactions to a bulletin board, wherein the bulletin board is accessible by all the parties;
• secretly share de-commitments among the parties, wherein each party-dependent de-commitment enables a verification to the party-dependent total value of the pending transactions as part of the commitment;
• compute, using a multi-party computation protocol, a revised balance after the multi-lateral netting in a process configured to handle the pending transactions;
• publish a determined liquidity status to the bulletin board;
• upon a determination of a failure in the publishing of the determined liquidity status, perform a secure fault-tolerant multi-party computation by a determination of whether all the pending transactions, regardless of an order of the pending transactions, are settable maintaining positive liquidity for each party of the parties;
• upon a determination of a failure in the determination of whether all the pending transactions are nettable, determine an optimized subset of transactions that are nettable without violation of liquidity requirements for each party of the parties via a Karmarkar algorithm;
• and
• determine a secret share and a commitment of a new balance for each party of the parties.