Cryptographic encoding and decoding of secret data

A distributed trust data processing system for cryptographically encoding and decoding data, comprising:

• a user computer, wherein said user computer is adapted to (i) generate a public key of a public-private keypair which is dependent on an event indicator (tω) indicative of a predetermined first event such that extraction of a private key (skθ) of said keypair is also dependent on occurrence of said event indicated by said event indicator (tω), (ii) use said public key to encode secret data in accordance with a verifiable encryption process which produces a cryptographic construction (θ) having a decryption constraint dependent on the occurrence of said predetermined first event, and (iii) send said cryptographic construction (θ) to said verifier computer via a data communications network;
• a key-extraction computer, wherein said key-extraction computer is adapted to respond to said request from said verifier computer by (i) determining if a predetermined decoding condition, dependent on occurrence of at least one event including said predetermined first event, exists (ii) extracting said private key (skθ) of said keypair and sending said private key (skθ) to said verifier computer if said predetermined decoding condition exists;
• and
• a verifier computer, wherein said verifier computer is adapted to (i) verify that said cryptographic construction (θ) contains said secret data, (ii) store said cryptographic construction (θ) in memory (10), (iii) communicate with said key extraction computer via said data communications network to request said private key (skθ) for said cryptographic construction (θ), and (iv) decode said cryptographic construction on receipt of said private key (skθ);
• wherein said user, verifier, and key-extraction computers are adapted for communication via said data communications network.