dynamic spectrum access (DSA) that promises to alleviate the spectrum shortage problem in wireless networks. By employing spectrum sensing techniques or referring to the geolocation databases, a CR (or a CR-enabled secondary user) is able to intelligently decide which licensed spectrum band is free for use without causing harmful interference to licensed (or primary) users. Besides, the spectru...

We propose a countermeasure against the so-called tailored bright illumination attack for differential-phase-shift QKD (DPS-QKD). By monitoring a rate of coincidence detection at a pair of superconducting nanowire single-photon detectors (SSPDs) which is connected at each of the output ports of Bob's Mach-Zehnder interferometer, Alice and Bob can detect and defeat this kind of attack. We also e...

A user-level operating system (OS) can be implemented as a regular user process on top of another host operating system. Conventional userlevel OSes, such as User Mode Linux, view the underlying host operating system as a specific hardware architecture. Therefore, the implementation of a user-level OS often requires porting of an existing kernel to a new hardware architecture. This paper propos...

Distributed Denial of Service (DDoS) attacks is virulent, relatively new type of attacks on the availability of Internet services and resources. DDoS attackers infiltrate large number of computers by exploiting software vulnerabilities, to set up DDoS attack networks. DDoS attacks pose an immense threat to the Internet, therefore some defense systems are required to defend these attacks. In thi...

Network emulation and simulation tools are widely used for preproduction, studies and researches purposes. This success is due to the quality of result they provide compared to the real equipments. Another advantage of the network simulators is that the cost of studies and experiences are exponentially reduced especially for networks that use expensive hardware or a big number of nodes. In the ...

Network-level emulation has recently been proposed as a method for the accurate detection of previously unknown polymorphic code injection attacks. In this paper, we extend network-level emulation along two lines. First, we present an improved execution behavior heuristic that enables the detection of a certain class of non-self-contained polymorphic shellcodes that are currently missed by exis...

This paper presents an architecture to assist in the development of tools to perform experimental analysis. Existing implementations of tools based on this architecture are also described in this paper. These tools are applied to the real world problem of fault attack emulation and detection in cryptographic algorithms. Keywords— Software Architectures and Design, Software Components and Reuse,...

Chertov, Roman Ph.D., Purdue University, May, 2008. A Device Independent Router Model: From Measurements to Simulations. Major Professors: Sonia Fahmy and Ness B. Shroff. Simulation, emulation, and wide-area testbeds exhibit different tradeoffs with respect to fidelity, scalability, and manageability. Network security and network planning/dimensioning experiments introduce additional requiremen...

We present the internals of QEMU, a fast machine emulator using an original portable dynamic translator. It emulates several CPUs (x86, PowerPC, ARM and Sparc) on several hosts (x86, PowerPC, ARM, Sparc, Alpha and MIPS). QEMU supports full system emulation in which a complete and unmodified operating system is run in a virtual machine and Linux user mode emulation where a Linux process compiled...