Patent ID: 11875340
Assignee: NCHAIN LICENSING AG
Field: Digital communication (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 4:
5. A computer-implemented method to participate in a data record distribution process using a blockchain, the data record distribution process including multiple input addresses and multiple output addresses, each address being controlled by a respective input node or output node, the computer-implemented method, implemented at one of a plurality of output nodes, comprising:
obtaining a key share of a first private key associated with the output nodes, the first private key being unknown to any of the output nodes, the first private key being associated with a first public key, wherein each of the output nodes has a respective key share of the first private key;
searching the blockchain for a first blockchain transaction containing a second public key associated with the input nodes, the first blockchain transaction identifying the multiple input addresses and having a stealth address as an output address;
obtaining a threshold number of first terms by calculating a first term and receiving further first terms from other output nodes, each first term being a term of a first Lagrange polynomial interpolation that includes a key share of the respective node and the second public key;
deriving a shared secret by summing said first terms;
determining the stealth address using the first public key and the shared secret and comparing the determined stealth address to the output address of the first blockchain transaction to confirm they match;
obtaining a threshold number of second terms by calculating a second term and receiving further second terms from other output nodes, each second term being a term of a second Lagrange polynomial interpolation that is derived from the key share of the respective node and the shared secret;
deriving a second private key using the sum of the second terms; and
signing, using an elliptic curve digital signature algorithm based on the second private key, a second blockchain transaction to distribute data records pooled in association with the stealth address to the multiple output addresses.