We give an overview of the running time analysis of the random divide-and-conquer algorithm FIND or QUICKSELECT. The results concern moments, distribution of FIND’s running time, the limiting distribution, a stochastic bound and the key: a stochastic fixed point equation.

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...

In this paper we propose a new protocol to manage multicast key distribution. The protocol is based on the use of orthogonal systems in vector spaces. The main advantage in comparison to other existing multicast key management protocols is that the length and the number of the messages which have to be sent are considerably smaller. This makes the protocol especially attractive when the number ...

Wireless sensor networks consist of sensor nodes with limited computational and communication capabilities. This paper deals with mobile sensors which are divided into clusters based on their physical locations. Efficient ways of key distribution among the sensors and inter and intra cluster communications are examined. The security of the entire network is considered through efficient key mana...

We revisit a key agreement scheme presented by Leighton and Micali [11], generalize the scheme, and present a new framework of tree-based key distribution pattern (TKDP). We presents a method of constructing TKDPs from cover-free families. We show the existence of TKDPs by probabilistic method. We can reduce the upper bounds on the minimum number of rows of (t, w, T )-TKDPs, which are obtained ...

Leveraging quantum mechanics, cryptographers have devised provably secure key sharing protocols[4], [3], [6], [17]. Despite proving the security in theory, real-world application falls short of the ideal. Last year, cryptanalysts completed an experiment demonstrating a successful eavesdropping attack on commercial quantum key distribution (QKD) systems[12]. This attack exploits a weakness in th...

Key establishment protocols are used for distributing shared keying material in a secure manner. In 1995, Bellare and Rogaway presented a three-party server-based key distribution (3PKD) protocol. But the protocol was recently found insecure and then was fixed by Raymond Choo et al.. But forward-secrecy is not considered in the revised protocol. In this paper, we demonstrate that it is not forw...

The pairwise key distribution scheme of Chan et al. was proposed as an alternative to the key distribution scheme of Eschenauer and Gligor to enable network security in wireless sensor networks. We consider the random graph induced by this pairwise scheme under the assumption of full visibility, and show the existence of a zero-one law for graph connectivity.

Key pre-distribution (KPD) schemes, which are inherently trade-offs between security and complexity, are perhaps well suited for securing large-scale deployments of resource constrained nodes without persistent access to a trusted authority (TA). However, the need to offset their inherent security limitations, calls for some degree of tamper-resistance of nodes. Obviously, if absolute tamperres...