Once a wireless sensor network (WSN) is stable and has been running for a while, sensors start to fail due to hardware problems, battery exhaustion or even due to their physical destruction. In any case, the administrator of the network may wish to replace the damaged nodes with new ones to reinforce the coverage area. In this paper we make use of an out of band channel (OOB) to bootstrap an au...

In mobile scenarios, privacy is an aspect of growing importance. In order to avoid the creation of movement profiles, participating nodes change their identifying properties on a regular basis in order to hide their identities and stay anonymous. The drawback of this action is that nodes which previously had a connection have no means to recognise this fact. A complete re-authentication would b...

A symmetric key encryption scheme is described for blocks of general size N that is a product of powers of many prime numbers. This is accomplished by realising each number (representing a message unit) as a point in a product of affine spaces over various finite fields. Then algebro-geometric transformations on those spaces is transported back to provide encryption. For a specific block size <...

08:30 – 09:30 Powhiri welcome Registration 08:00 – 17:10 09:30 – 10:30 Jennifer Seberry Lecture: Prof. Clark Thomborson 10:30 – 10:50 Coffee break 11:50 – 12:30 Regular papers – Session 1A + 1B 12:30 – 13:20 Lunch 13:20 – 14:00 Invited Talk 1: A/Prof Henry B Wolfe 14:00 – 15:15 Regular papers – Session 2A + 2B 15:15 – 15:40 Coffee break 15:40 – 16:30 Regular papers Session 3A+ 3B 16:30 – 17:00 ...

In this work, we introduce a symmetric algorithm obtained by the recurrence relation an = a k n−1+a k−1 n . We point out that this algorithm can be apply to hyperharmonic-, ordinary and incomplete Fibonacciand Lucas numbers. An explicit formulae for hyperharmonic numbers, general generating functions of the Fibonacciand Lucas numbers are obtained. Besides we define ”hyperfibonacci numbers”, ”hy...

At CHES 2006, a DPA countermeasure based on the Fourier Transform was published. This generic countermeasure aims at protecting from DPA any S-box calculation used in symmetric cryptosystems implementations. In this paper, we show that this countermeasure has a flaw and that it can be broken by first order DPA. Moreover, we have successfully put into practice our attack on two different S-box i...

From .. to .., the Dagstuhl Seminar 07021 Symmetric Cryptography was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put toget...