Bitcoin users are directly or indirectly forced to deal with public key cryptography, which has a number of security and usability challenges that differ from the password-based authentication underlying most online banking services. Users must ensure that keys are simultaneously accessible, resistant to digital theft and resilient to loss. In this paper, we contribute an evaluation framework f...

Pseudo-random functions (PRFs) introduced by Goldwasser, Goldreich, and Micali (FOCS 1984), are one of the most important building blocks in cryptography. A PRF family is a family of seeded functions {fs}, with the property that no efficient adversary can tell the difference between getting oracle access to a random PRF function fs, and getting oracle access to a truly random function. In this ...

Leakage resilient cryptography aims to address the issue of inadvertent and unexpected information leakages from physical cryptographic implementations at algorithmic level in a provable manner. In real world, for an abstract mathematical construction to be an actual physical implementation, it usually undergoes two phases: mathematical realization at algorithmic level and physical realization ...

To detect replica nodes in a wireless sensor network, we propose a distributed, deterministic and resilient (DDR) replica detection protocol developed from a witness node based strategy. In DDR, while a location claim message of each node is sent towards the designated verification location in the network, the consistency of the messages is verified at intermediate nodes en route to its final d...

RFC 3227 provides general guidelines for digital evidence collection and archiving, while the International Organization on Computer Evidence offers guidelines for best practice in the digital forensic examination. In the light of these guidelines we will analyze integrity protection mechanism provided by EnCase and FTK which is mainly based on Message Digest Codes (MDCs). MDCs for integrity pr...

The aim of the project was to investigate the application of security protocol analysis techniques to security APIs. Security protocols are short programs that describe the secure exchange of information over an insecure network, using cryptography. Security APIs are the Application Program Interfaces of tamper-resistant hardware security modules, commonly used in security critical applications...

Cryptographic puzzles can be used to mitigate spam and denial-of-service (DoS) attacks, as well as to implement timed-release cryptography. However, existing crypto puzzles are impractical because: (1) solving them wastes computing resources and/or human time, (2) the time it takes to solve them can vary dramatically across computing platforms, and/or (3) applications become non-interoperable d...

This report deals with security in wireless sensor networks (WSNs), especially in network layer. Multiple secure routing protocols have been proposed in the literature. However, they often use the cryptography to secure routing functionalities. The cryptography alone is not enough to defend against multiple attacks due to the node compromise. Therefore, we need more algorithmic solutions. In th...