This paper is concerned with key escrow protocols for use in international communications environments, where communication domains do not necessarily trust one another. It is concerned particularly with systems where users place their trust collectively with groups of trusted third parties. We consider two diierent protocols, discuss and improve their eeciency and generalise the type of key sp...

We propose quantum secret sharing scheme that emphasizes on the cooperation (twice) of communicating parties to avoid untrustworthy members and improves the strength of the key. The proposed scheme is a new approach in quantum secret sharing in which cooperation of the parties is emphasized at the same time the key is strengthened by performing a shift operation on the received partial keys. In...

We improve a secret sharing scheme, which enables users select their personal keys by themselves instead of being distributed by group manager and users can reuse their personal keys no matter the shared secret is renewed or recovered. Then we apply it to design a self-healing key distribution scheme. The new scheme achieves good properties. Firstly, the scheme reduces storage overhead of perso...

• The insider and outsider attacks against the improved version (Subsection 3.1, Methods 1 and 2; Subsection 3.2 Method 1) are limited by the success of a guessing attack against the hash function. We highlight that the attacks assume the guessing of a random number (not a password, which would have been feasible!). Hence, if the hash function is properly selected, the attacks are infeasible1. ...

In 1992, a non-interactive k-secure m-conference protocol based on an m-variate polynomial has been proposed. Each user needs to store a (m 1)-polynomial having degree k as a private share. A secret conference key involving m users can be computed by each conference member non-interactively using each private share. There is no overhead to exchange information in order to establish a conference...

Many organisations enforce policies on the length and formation of passwords to encourage selection of strong passwords and protect their multi-user systems. For Two-Server Password Authenticated Key Exchange (2PAKE) and Two-Server Password Authenticated Secret Sharing (2PASS) protocols, where the password chosen by the client is secretly shared between the two servers, the initial remote regis...

A prerequisite for secure communication between two nodes in an ad hoc network is that the nodes share a key to bootstrap their trust relationship. In this paper, we present a scalable and distributed protocol that enables two nodes to establish a pairwise shared key on the fly, without requiring the use of any on-line key distribution center. The design of our protocol is based on a novel comb...

Efficient key establishment is an important problem for secure group communications. The communication and storage complexity of group key establishment problem has been studied extensively. In this paper, we propose a new group key establishment protocol whose computation complexity is significantly reduced. Instead of using classic secret sharing, the protocol only employs a linear secret sha...

We propose a cryptosystem that has an inherent key escrow mechanism. This leads us to propose a session based public verifiable key escrow system that greatly improves the amount of key material the escrow servers has to keep in order to decrypt an encryption. In our scheme the servers will only have a single secret sharing, as opposed to a single key from every escrowed player. This is done wh...