Hyunrok Lee

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Lee et al. [4] proposed two new authenticated multiple key exchange protocols based on Elliptic Curve Cryptography (ECC) and bilinear pairings. In this paper, we show an impersonation attack on their pairing-based authenticated key exchange protocol. We demonstrate that any attacker can impersonate an entity to share multiple session keys with another(More)
Keywords: On-line/off-line Threshold signatures Double-trapdoor Chameleon hashing Key exposure problem a b s t r a c t The ''hash–sign–switch " paradigm was firstly proposed by Shamir and Tauman with the aim to design an efficient on-line/off-line signature scheme. Nonetheless, all existing on-line/off-line signature schemes based on this paradigm suffer(More)
It is considered to be the most suitable solution for large scale elections to design an electronic voting scheme using blind signatures and anonymous channels. Based on this framework, Okamoto first proposed a receipt-free voting scheme [23] for large scale elections. However , in the following paper, Okamoto [24] proved that the scheme [23] is not(More)
RFID (Radio Frequency Identification) is recently becoming popular, promising and widespread. In contrast, RFID tags can bring about traceability that causes user privacy and reduces scalability of RFID. Guaranteeing untraceability and scalability at the same time is so critical in order to deploy RFID widely since user privacy should be guaranteed. A large(More)
Group key management presents a fundamental challenge in secure dynamic group communications. In this paper, we propose an efficient group authenticated key agreement protocol (EGAKA), which is designed to be fully distributed and fault-tolerant, provides efficient dynamic group membership management, mutual authentication among group members and is secure(More)
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