We propose a new unidirectional proxy re-encryption scheme based on the hardness of the LWE problem. Our construction is collusionsafe and does not require any trusted authority for the re-encryption key generation. We extend a recent trapdoor definition for a lattice of Micciancio and Peikert. Our proxy re-encryption scheme is provably CCA-1 secure in the selective model under the LWE assumption.

With the popularization of wireless network, security issue is more and more important. When IEEE 802.11i draft proposed TKIP, it is expected to improve WEP (Wired Equivalent Privacy) on both active and passive attack methods. Especially in generating and management of secret keys, TKIP uses more deliberative attitude to distribute keys. Besides, it just upgrades software to accomplish these fu...

Generating secret keys using physical properties of the wireless channel has recently become a popular research area. The main security assumption of these protocols is that a sufficiently distant adversary is unable to guess a generated secret due to the unpredictable behavior of multipath signal propagation. In this paper, we introduce a practical and efficient man-in-the-middle attack agains...

Many techniques have been proposed to generate keys including text passwords, graphical passwords, biometric data and etc. Most of these techniques are not resistant to coercion attacks in which the user is forcefully asked by an attacker to generate the key to gain access to the system or to decrypt the encrypted file. We present a novel approach in generating cryptographic keys to fight again...

In this paper, we pioneer a key security level gradation scheme which is proved to efficient to counteract Iterative-Encrypting-Attack against RSA. And we make it clear that the bug which hides after the traditional key generation algorithm is exploited by Iterative-EncryptingAttack and weakens RSA security, and that the case can be improved if the traditional key generation algorithm is modifi...

This paper presents a protocol called SAKE (Software Attestation for Key Establishment), for establishing a shared key between any two neighboring nodes of a sensor network. SAKE guarantees the secrecy and authenticity of the key that is established, without requiring any prior authentic or secret information in either node. In other words, the attacker can read and modify the entire memory con...

User authentication is a critical part of security, along with confidentiality and integrity, for computer systems that allow legitimate users remote access over an open communication network. Recently, user authentication for wireless sensor networks (WSNs) has received considerable attention. We propose a robust user authentication scheme for WSNs. The scheme is based on elliptic-curve crypto...

In this paper, we propose an enhanced version of the HB-MP authentication protocol, called the HB-MP protocol. The HB-MP protocol is a lightweight authentication protocol that is suitable for use in passive radio frequency identification (RFID) systems. The HB-MP protocol overcomes the man-in-the-middle attack to which the basic HB-MP protocol is vulnerable while maintaining its suitability to ...

In this paper, we show that the certificateless signature scheme proposed by Yap, Heng and Goi at SecUbiq 2006 is insecure against a key replacement attack and a malicious-but-passive KGC attack, respectively. The former implies that anyone who replaces a signer’s public key can forge valid signatures for that signer without knowledge of the signer’s private key. The latter supposes the malicio...

Password-authenticated key exchange (PAKE) is where a client and a server, who share a password, authenticate each other and meanwhile establish a cryptographic key by exchange of messages. The main aim of this project is to authenticate a client, in the scenario where two Peer servers co-operate for Authentication and if one server is compromised, the attacker still cannot pretend to be the cl...