Asynchronous Information Checking Protocol (AICP) Clause Samples
Asynchronous Information Checking Protocol (AICP). An ICP is used for authenticating data in the presence of computationally unbounded corrupted parties. The notion of ICP was first introduced by ▇▇▇▇▇ et al. [26]. As described in [26, 8, 11], an ICP is executed among three parties: a Signer, an intermediary INT and a Verifier. Informally, an ICP con- sists of two stages, implemented by different protocol(s): – Signature-generation stage: it consists of two phases. In the first phase, Signer computes its IC (information checking) signature on a secret s F, denoted by ICSig( Signer, INT, Verifier, s) and hands it to INT. Signer also computes some verification information for Verifier and hands it to Verifier. In the second phase, INT (in co- operation with Signer and Verifier) confirms whether in- deed the received signature is a “valid” signature. – Signature-revelation stage: here INT reveals the signa- ture ICSig(Signer, INT, Verifier, s), claiming that it has received it from Signer. Verifier then verifies the sig- nature, using the verification information and either ac- cepts or rejects the signature (and hence s). An IC signature may be considered as the information-theo- retically secure variant of digital signatures. It provides pro- perties like unforgeability and non-repudiation; in addition, it provides information-theoretic security of the secret. That is, if Signer and INT are honest, then at the end of signature- generation stage, a corrupted Verifier does not learn any in- formation about s in the information-theoretic sense. We extend the notion of ICP in two directions: Firstly, we consider multiple verifiers, where each party in acts as a Verifier. Looking ahead, the multiple-verifier ICP con- cept readily fits in our AWC protocol; note that Signer and INT can be any two parties from the set . Secondly, instead of a single secret, we consider ICP that can deal with mul- tiple secrets concurrently; later this allows to achieve bet- ter communication complexity, than executing multiple in- stances of ICP, dealing with a single secret. Our ICP is exe- cuted in the asynchronous setting and thus we call it AICP. Definition 4 ((Multi-Verifier) Asynchronous Informatio n Checking Protocol (AICP)) An AICP involves three en- tities: a Signer , an intermediary INT and the set of parties acting as verifiers. The protocol is carried out in three phases, each implemented by a different sub-protocol:
Asynchronous Information Checking Protocol (AICP). An Information Checking Protocol (ICP) is used for authen- ticating data in the presence of computationally unbounded corrupted parties. The notion of ICP was first introduced by ▇▇▇▇▇ et al. [29]. As described in [29, 9, 12], an ICP is exe- cuted among three parties: a Signer, an intermediary INT and a Verifier. Informally, an ICP consists of two phases (where each phase is implemented by different protocol(s)): – Signature generation phase: here Signer computes his IC (information checking) signature on a secret s F, denoted by ICSig(Signer, INT, Verifier, s) and hands it to INT. Signer also computes some verification infor- mation and hands it to Verifier. – Signature revelation phase: here INT reveals the signa- ture ICSig(Signer, INT, Verifier, s), claiming that he has received it from Signer. Verifier then verifies the sig- nature, using the verification information and either ac- cepts or rejects the signature (and hence s). IC signature may be considered as the information theoret- ically secure substitute of traditional digital signatures. It provides the properties like unforgeability and non-repudiation; in addition, it also provides information theoretic security. That is, if Signer and INT are honest, then at the end of the signature generation phase, s remains secure in the informa- tion theoretic sense. We extend the above notion of ICP in two directions: First, we consider multiple verifiers, where each party in acts as a Verifier. This will be later helpful in using the ICP as a tool in our AWC protocol. It is important here to note that Signer and INT can be any two parties from the set . They just play their “special” role as Signer and INT. Sec- ond, instead of a single secret, we consider ICP that can deal with multiple secrets concurrently and thus achieves better communication complexity, than executing multiple instances of ICP, dealing with a single secret. Our ICP is ex- ecuted in the asynchronous settings and thus we call it AICP. We now formally define AICP. Definition 4 ((Multi-Verifier) Asynchronous Information Checking Protocol (AICP)) An AICP involves three enti- ties: a Signer , an intermediary INT and the set of n parties in acting as verifiers. The protocol is carried out in three phases (where each phase is implemented by a protocol):