Ik Rae Jeong

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Cryptographic protocol design in a two-party setting has often ignored the possibility of simultaneous message transmission by each of the two parties (i.e., using a duplex channel). In particular, most protocols for two-party key exchange have been designed assuming that parties alternate sending their messages (i.e., assuming a bidirectional half-duplex(More)
In the last few years, researchers have extensively studied the password-authenticated key exchange (PAKE) in the three-party setting. The fundamental security goal of PAKE is security against dictionary attacks. The protocols for verifier-based PAKE are additionally required to be secure against server compromise. Some verifier-based PAKE schemes in the(More)
To make authenticated encryption which provides confidentiality and authenticity of a message simultaneously, a signcryption scheme uses asymmetric primitives, such as an asymmetric encryption scheme for confidentiality and a signature scheme for authentication. Among the signcryption schemes, the hybrid signcryption schemes are the signcryption schemes(More)
In this paper, we propose a key agreement protocol for a key hypergraph. In a key hypergraph, a party is represented as a vertex and a group of parties is represented as a hyperedge. A key agreement protocol for a key hypergraph establishes all the keys for hyperedges in a key hypergraph at the same time. A naive approach would be to run a group key(More)
We suggest a linkable ring signature scheme providing strong anonymity and weak linkability. We show that our linkable ring signature scheme can be used to construct a selectively linkable ring signature scheme, an efficient convertible (verifiable) ring signature scheme, and an efficient deductible ring signature scheme.