In some embodiments, the at least one first computing device sends the recovery private key to a recovery escrow service, the at least one first computing device periodically sends an arbitrary message to the recovery escrow service, wherein the recovery message is signed by the recovery private key, the signed arbitrary message is published in a public repository, the at least one second computing device retrieves the signed arbitrary message from the public repository, the at least one second computing device verifies that the encryption of the signed arbitrary message is compatible with the recovery public key, and the at least one second computing device verifies that the recovery escrow service has the recovery private key. In some embodiments, the encryption is carried out using a verifiable homomorphic ElGamal encryption.

There is thus provided, in accordance with some embodiments of the invention, a system for recovery of a cryptographic key associated with a blockchain based computer network, the system including: at least one first computing device, configured to: encrypt at least a portion of a cryptographic key of the computer network with a recovery public key, and send a recovery private key to a recovery escrow service, at least one second computing device, in communication with the at least one first computing device, and configured to: receive the encrypted at least a portion of the cryptographic key from the at least one first computing device, detect that the at least one first computing device is unavailable, retrieve the recovery private key from a public repository, wherein the recovery private key is published by the recovery escrow service, and decrypt the encrypted at least a portion of the cryptographic key.