In some embodiments, the recovery escrow service stores the recovery private key, and instructions to publish the recovery private key are provided by a third party. In some embodiments, the third party periodically publishes a status report of the at least one first computing device in a public repository to be retrieved by the at least one second computing device. In some embodiments, the recovery escrow service is on an external computing device. In some embodiments, the at least one second computing device includes a mobile computing device. In some embodiments, the at least one second computing device is connected to the computer network, and a transaction is added to a ledger of the computer network, in accordance with the received signed at least a portion of the cryptographic key.

There is thus provided, in accordance with some embodiments of the invention, a method of verifying that an encrypted cryptographic private key associated with a blockchain based computer network can be decrypted, the method including: encrypting, by at least one first computing device, at least a portion of a cryptographic key of the computer network with a recovery public key, wherein the encryption is carried out using an homomorphically additive encryption scheme, sending, by the at least one first computing device, the encrypted at least a portion of the cryptographic key to at least one second computing device, retrieving, by at least one second computing device, the recovery public key from the at least one first computing device; and verifying, by the at least one second computing device, that the encrypted at least a portion of the cryptographic key is compatible to be decrypted by a recovery private key, based on the retrieved recovery public key and the corresponding public key of the at least a portion of the cryptographic key.