Combinatorial problems serve as an important resource for developing practical public key cryptosystems and several combinatorial cryptosystems have been proposed in the cryptographic community. In this paper, a combinatorial public key cryptosystem is proposed. The security of the proposed cryptosystem is dependent on a combinatorial problem involving matrices. The system features fast encrypt...

Certificateless cryptosystems were proposed by Al-Riyami and Paterson in 2003 [1] to solve problems of public key cryptosystems based on PKI and based on identity. Up to now, various types of certificateless cryptographic primitives as encryption functions, signature schemes, key agreement protocols and etc, have been designed. But to the best of our knowledge, multiple-key agreement protocols ...

Lamport [1] presented lower bound results on the number of acceptors required as a function of the number of processes that can fail so that fast asynchronous consensus can be achieved in the byzantine setting for favourable runs. The lower bounds presented assume that processes can use public-key cryptography during the computation. We explore how the lower bound results change if the public-k...

Multiplicative inverse is a crucial operation in public key cryptography, and been widely used in cryptography. Public key cryptography has given rise to such a need, in which we need to generate a related public and private pair of numbers, each of which is the inverse of the other. The basic method to find multiplicative inverses is Extended-Euclidean method. In this paper we will propose a n...

We demonstrate that the public key cryptosystems using the modular group suggested in [4,5] are vulnerable to very simple ciphertextonly attacks. Consequently, in the present form both of these systems cannot be considered as sufficiently secure for cryptographic purposes.

Key distribution and management is the foundation of any secure services of wireless sensor networks. Due to the resource constraints, establishing cryptographic keys between communicating sensors in large-scale wireless sensor networks is a big challenge. Traditional asymmetric key cryptography is not suitable for wireless sensor environment because of its complexity. Based on the polynomial-k...

Wireless Sensor Network (WSN) consists of huge number of sensor nodes which are small and inexpensive with very limited resources. The public key cryptography is undesirable to be used in WSN because of the limitations of the resources. A key management and predistribution techniques are required to apply the symmetric key cryptography in such a big network. Many key predistribution techniques ...

A new formal security model for session key exchange protocols in the public key setting is proposed, and several eecient protocols are analyzed in this model. The relationship between this new model and previously proposed models is explored, and several interesting, subtle distinctions between static and adaptive adversaries are explored. We also give a brief account of anonymous users.

At Eurocrypt'95, Desmedt suggested a scheme which allows individuals to en-crypt in such a way that the receiver can be traced by an authority having additional information. This paper shows that the proposed scheme does not have the required properties, by devising three non-speciied protocols misleading the authority. We also discuss how to repair Desmedt's scheme, such that our attacks are n...