An example operation may include one or more of connecting, by a recipient node, to a source node via a blockchain network, receiving, by the recipient node, a data block, a digest of the data block encrypted by a private key of the source node, a public key paired to the private key and an IP address of the source node, calculating, by the recipient node, a digest of the data block, decrypting, by the recipient node, the digest of the data block by the public key, comparing, by the recipient node, the decrypted digest against the digest, and in response to a match, storing the encrypted digest, the public key and the IP address of the source node onto a ledger of the recipient node.