Method and system for inter-dlt networks trust enhancement

A system for enhancing the level of trust of a first Distributed Ledger Technology, DLT, network using one or more second DLT networks, where the first and the second DLT networks are independent DLT networks connected by one or more telecommunications networks, the system comprising the first DLT network and one or more second DLT networks, the first DLT network comprising at least one computing node comprising a processor configured to:

• receive a request to validate a smart contract, where for the validation of the smart contract a certain trust policy is used;
• compute a hash value h(i) which identifies uniquely the current execution of the smart contract correspondent to the trust policy and its result, and store said hash value in a database of the first DLT network;
• obtain the hash value of the previous execution of the smart contract h(i−1);
• transmit to a computing node of each second DLT network a validation instruction including h(i) and a zero-knowledge proof, prf(i) being prf(i)=Proof(Pk, hp(i), diff(i)), where Proof( ) is a pre-established function, Pk is a pre-established random proof key, diff(i)=h(i)−h(i−1) and hp(i)=hash(h(i)∥diff(i));
• the one or more second DLT networks comprising:
• at least one computing node comprising a processor configured to receive the validation instruction from the first DLT network directly or through another computing node of the second DLT network;
• determine a validation result by calculating:
• Verify (Vk, hp(i), prf(i)) where Verify( ) is a pre-established verification function, Vk is a pre-established random verification key, hp(i)=hash(h(i)∥diff(i)), and diff(i)=h(i)−h(i−1) where h(i) is the value of h(i) received from the first DLT network and h(i−1) is the hash value stored in the computing node in the previous execution of the validation for the smart contract;
• where the execution of the smart contract in the first DLT network is aborted, if the number of negative validation results received from the one or more second DLT networks is higher than a pre-established threshold.