Privacy-preserving leakage-deterring public-key encryption from attribute-based encryptions

An apparatus, comprising:

• at least one memory having computer readable code thereon;
• and
• at least one processor, wherein the at least one processor causes, in response to retrieval and execution of the computer readable code, the apparatus to perform operations comprising:
• performing a commitment scheme by a sender system with a first system so both the sender system and first system have at least a first signature, the commitment scheme comprising:
• sending, as part of the commitment scheme and from the sender system, which has access to leakage-deterring data, to the first system, a commitment to the leakage-deterring data;
• proving, as part of the commitment scheme and in zero-knowledge, by the sender system to the first system, that the sender system has access to an opening to the commitment;
• and
• receiving, at the sender system and from the first system and as part of the commitment scheme, the first signature built from signing both a commitment to the leakage-deterring data of the sender system and an identifier of the sender system, and being the same first signature at the sender and first system;
• encrypting, in response to successful completion of the commitment scheme, a message by applying a one-time pad to the message using a one-time-pad key to create a first encrypted message;
• encrypting the first encrypted message with a public key of a receiver system to create a second encrypted message;
• encrypting, by the sender system, the one-time-pad key with an attribute-based encryption scheme, for which the attributes are predefined time period data and a receiver system identifier related to the receiver system, with a public key of a second system;
• forming, by the sender system, a ciphertext from a combination of the second encrypted message and the encrypted one-time-pad key;
• and
• sending, by the sender system, the formed ciphertext to the receiver system for use by the receiver system in performing a second commitment scheme with the second system to prove at least possession of a second signature from the first system, and for use by the receiver system for decryption after the receiver system has performed the second commitment scheme.

A computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by an apparatus to cause the apparatus to perform operations comprising:

• performing a commitment scheme by a sender system with a first system so both the sender system and first system have at least a first signature, the commitment scheme comprising:
• sending, as part of the commitment scheme and from the sender system, which has access to leakage-deterring data, to the first system, a commitment to the leakage-deterring data;
• proving, as part of the commitment scheme and in zero-knowledge, by the sender system to the first system, that the sender system has access to an opening to the commitment;
• and
• receiving, at the sender system and from the first system and as part of the commitment scheme, the first signature built from signing both a commitment to the leakage-deterring data of the sender system and an identifier of the sender system, and being the same first signature at the sender and first system;
• encrypting, in response to successful completion of the commitment scheme, a message by applying a one-time pad to the message using a one-time-pad key to create a first encrypted message;
• encrypting the first encrypted message with a public key of a receiver system to create a second encrypted message;
• encrypting, by the sender system, the one-time-pad key with an attribute-based encryption scheme, for which the attributes are predefined time period data and a receiver system identifier related to the receiver system, with a public key of a second system;
• forming, by the sender system, a ciphertext from a combination of the second encrypted message and the encrypted one-time-pad key;
• and
• sending, by the sender system, the formed ciphertext to the receiver system for use by the receiver system in performing a second commitment scheme with the second system to prove at least possession of a second signature from the first system, and for use by the receiver system for decryption after the receiver system has performed the second commitment scheme.