Wouter Bokslag

Wouter Bokslag, Manon de Vries

In the Netherlands as well as many other countries, the use of electronic voting solutions is a recurrent topic of discussion. While electronic voting certainly has advantages over paper voting, there are also important risks involved. This paper presents an analysis of benefits and risks of electronic voting, and shows the relevance of these issues by means of three case studies of real-world implementations. Additionally, techniques that may be employed to improve upon many of the current systems are presented. We conclude that the advantages of E-voting do not outweigh the disadvantages, as the resulting reduced verifiability and transparency seem hard to overcome.

Wouter Bokslag

This paper will discuss the Logjam attack on TLS. The Logjam attack allows, under certain conditions, to defeat the security provided by TLS. This is done by manipulating server and client into using weak and deprecated export grade crypto, and subsequently breaking the Diffie-Hellman key exchange. We explore how the attack works conceptually and how exactly TLS is vulnerable to this attack. Also, the conditions under which the attack can be mounted are discussed, and an estimate of the impact of the attack is presented. Lastly, several mitigations are presented.

Jos Wetzels, Wouter Bokslag

In this document we present an introductory overview of the algorithms and design components underlying the Keccac cryptographic primitive and the Keyak encryption scheme for authenticated (session-supporting) encryption. This document aims to familiarize readers with the basic principles of authenticated encryption, the Sponge and Duplex constructions (full-state, keyed as well as regular versions), the permutation functions underlying Keccak and Keyak as well as Keyak v2's Motorist mode of operation.

Jos Wetzels, Wouter Bokslag

In this paper we will present various hardware architecture designs for implementing the SIMON 64/128 block cipher as a cryptographic component offering encryption, decryption and self-contained key-scheduling capabilities and discuss the issues and design options we encountered and the tradeoffs we made in implementing them. Finally, we will present the results of our hardware architectures' implementation performances on the Xilinx Spartan-6 FPGA series.

Wouter Bokslag

This paper discusses the relevance and potential impact of both RFID and reverse engineering of RFID technology, followed by a discussion of common protocols and internals of RFID technology. The focus of the paper is on providing an overview of the different approaches to reverse engineering RFID technology and possible countermeasures that could limit the potential of such reverse engineering attempts.