There may be provided a computer-implemented method. It may be implemented at least in part using a blockchain network such as, for example, the Bitcoin network. The computer-implemented method includes: i) encrypting a plaintext message to a cryptographic public key in accordance with an identity-based encryption scheme using at least a congress public key to generate an encrypted message, wherein the congress public key is associated with members of a congress, respective members of the congress having access to private key shares usable in a threshold decryption scheme in which at least a threshold of private key shares are sufficient to derive a decryption key through the combination of partial contributions to the decryption key on behalf of the congress; ii) generating, using at least a cryptographic private key corresponding to the cryptographic public key, a digital signature over a first set of instructions to perform cryptographic operations upon an occurrence of an event; and iii) broadcasting one or more transactions to a proof-of-work blockchain network, the one or more transactions comprising the encrypted message, the cryptographic public key, at least the first set of instructions, and a second set of instructions to the members of the congress to cooperate to: in response to reaching a consensus on the event occurring and contingent upon the digital signature being authentic, deploy a ghost chain to perform the first set of instructions, wherein performing the first set of instructions includes at least deriving the decryption key from the cryptographic key and a plurality of private key shares that satisfies the threshold, the decryption key being sufficient cryptographic material to obtain the plaintext message from the encrypted message.