Forward-secure and quantum-attack-resistant updatable attribute-based conditional proxy re-encryption method

A system for forward-secure and quantum-attack-resistant updatable attribute-based conditional proxy re-encryption, the system comprising one or more processors configured to execute instructions to perform operations comprising:

• generating and disclosing a public parameter based on a security parameter;
• generating public-private key pairs for both a delegator and a delegatee based on the public parameter;
• encrypting a plaintext based on the public parameter, a public key of the delegator, and an attribute vector to generate a ciphertext, and sending the ciphertext to a re-encryption component;
• generating an updated public key for the delegatee and an updated ciphertext for updating a private key of the delegatee, based on a public key of the delegatee;
• generating a re-encryption key associated with a control strategy based on the public parameter, the public-private key pair of the delegator, an updated public key of the delegatee, and the control strategy;
• re-encrypting the ciphertext using the re-encryption key by the re-encryption component to generate a re-encrypted ciphertext, and sending the re-encrypted ciphertext to the delegatee;
• generating an updated private key based on the private key of the delegatee and the updated ciphertext for updating the private key of the delegatee;
• and
• decrypting the ciphertext or the re-encrypted ciphertext based on the public parameter, the private key of the delegator, and the updated private key of the the delegatee.

A non-transitory computer-readable storage medium storing instructions that, when executed by one or more processors, cause the processors to perform a method comprising:

• generating and disclosing a public parameter based on a security parameter;
• generating public-private key pairs for both a delegator and a delegatee based on the public parameter;
• encrypting a plaintext based on the public parameter, a public key of the delegator, and an attribute vector to generate a ciphertext, and sending the ciphertext to a re-encryption component;
• generating an updated public key for the delegatee and an updated ciphertext for updating a private key of the delegatee, based on a public key of the delegatee;
• generating a re-encryption key associated with a control strategy based on the public parameter, the public-private key pair of the delegator, an updated public key of the delegatee, and the control strategy;
• re-encrypting the ciphertext using the re-encryption key by the re-encryption component to generate a re-encrypted ciphertext, and sending the re-encrypted ciphertext to the delegatee;
• generating an updated private key based on the private key of the delegatee and the updated ciphertext for updating the private key of the delegatee;
• and
• decrypting the ciphertext or the re-encrypted ciphertext based on the public parameter, the private key of the delegator, and the updated private key of the the delegatee.