Xiaochao Li

Efficient implementation for MD5-RC4 encryption using GPU with CUDA

Benefit from the novel Compute Unified Device Architecture (CUDA) introduced by NVIDIA, Graphics Processing Unit (GPU) turns out to be a promising solution for cryptography applications. In this paper we present an efficient implementation for MD5-RC4 encryption using NVIDIA GPU with novel CUDA programming framework. The MD5-RC4 encryption algorithm was implemented on NVIDIA GeForce 9800GTX GPU. The performance of our solution is compared with the implementation running on an AMD Sempron Processor LE-1200 CPU. The results show that our GPU-based implementation exhibits a performance gain of about 3–5 times speedup for the MD5-RC4 encryption algorithm.

AES finalists implementation for GPU and multi-core CPU based on OpenCL

Benefit from the OpenCL (Open Computing Language), applications can be easily transplanted among different GPUs, multi-core CPUs, and other processors. In this paper, we present implementation of AES finalists (Rijndael, Serpent, Twofish) in XTS mode, based on OpenCL. Benchmark testing is performed on 4 mainstream GPUs and multi-core CPUs. The results are also compared with implementations based on traditional serial programming model and CUDA. The resulting data shows that throughputs based on OpenCL are higher than serial programming model, while a little lower than CUDA. Which demonstrates that OpenCL promises a portable language for GPU programming, while entail a performance penalty.

Efficient architectures of MDCT/IMDCT implementation for MPEG audio codec

Efficient architectures for realizing MDCT/IMDCT are presented. Based on the symmetry property of trigonometric functions, N-point MDCT formula will be transferred into an odd-even index paralleling process which can be achieved by two different types of decomposition, recursive formed DCT-II kernel or FFT-based DCT-IV kernel. Then a butterfly unit is employed to accelerate the computational speed. Furthermore, these new architectures are suitable for the computations of both MDCT and IMDCT, which improve the hardware efficiency. For verification, an experiment of MPEG2 AAC using this optimized FFT-based MDCT architecture on Altera Stratix FPGA is implemented. The analyzed results show the proposed structure provides a superior performance in terms of the computation rate, the data throughput and the hardware utilization. In addition, these MDCT/IMDCT architectures can be employed in many international audio standard systems.

A new method of test data generation for branch coverage in software testing based on EPDG and Genetic Algorithm

A new method called EPDG-GA which utilizes the Edge Partitions Dominator Graph (EPDG) and Genetic Algorithm (GA) for branch coverage testing is presented in this paper. First, a set of Critical Branches (CBs) are obtained by analyzing the EPDG of the tested program, while covering all the CBs implies covering all the branches of the Control Flow Graph (CFG). Then, the fitness functions are instrumented in the right position by analyzing the Pre-Dominator Tree (PreDT), and two metrics are developed to prioritize the CBs. Coverage-Table is established to record the CBs information and keeps track of whether a branch is executed or not. GA is used to generate test data to cover CBs so as to cover all the branches. The comparison results show that this approach is more efficient than random testing approach.

A path-oriented test data generation approach for automatic software testing

The clonal selection (CS) algorithm is an optimization algorithm based upon the clonal selection principle in the biological immune system. This paper presents a novel approach that uses CS algorithm for path-oriented test data generation. The approach takes a selected path as a target and executes sequences of operators iteratively for test case to generate. An affinity function which is made up of a similarity and penalty value is developed to guide the test generator to make successive modifications of the test data, so that test data can ever closer to satisfy the requirement. The comparison results show that this approach is more efficient than those based on other heuristic algorithms in finding solutions.

Implementations of hardware acceleration for MD4-family algorithms based on GPU

The MD4-family algorithms have been widely applied in cryptographic field. Nowadays, it is discovered that MD4-family algorithms are also suitable for random number generators. Since the MD4-family algorithms are computing intensive, they can be accelerated on Graphics Processing Units (GPUs) to generate massive high-quality random numbers. This paper presents acceleration of MD4-family algorithms based on GPU, and the results show that these implementations achieve 100 times speedup over AMD Sempron Processor LE-1200 CPU.

Design and implementation of a debugging system for OpenRISC processor

A gdb-based debugging system for OpenRISC1200 Processor based on IEEE1149.1 JTAG interface is developed. Unlike usual gdb-based embedded debugging systems, this system uses the hardware debugging modules in OpenRISC1200 Processor to extend GDB. Its debugging agent doesnpsilat work on the target but on the host computer, so it can work well without any target operating system support. In this paper, the systempsilas general frame design and realization of the main modules are explained in detail. It is verified by both FPGA prototype emulation and software simulation. It establishes a good foundation for further development on OpenRISC.

The security of key derivation functions in WINRAR

In various versions of WINRAR, the file security is mainly protected by user authentication and files encryption. Password based key derivation function (PBKDF) is the core of the WINRAR security mechanism. In this paper, the security of PBKDF algorithm and the encrypted file in WINRAR are analyzed by the Game-Playing approach. We show the upper boundary of the Adversary’s Advantage over the random function. With the theoretical derivation, the actual safety of the WINRAR encrypted files has been discussed. According to the latest developments for GPU-based exhaustive password search attacks, we do some experiments and draw a conclusion that if the length of password is longer than 6, the WINRAR and later versions are secure.

On the security of key derivation functions in office

In Microsoft Office, the file security is mainly protected by user authentication and files encryption. The cryptographic keys are usually derived from a password. Thus, password based key derivation function (PBKDF) is the core of the security scheme. However, the security of the PBKDF of Office is not yet ensured. In this paper, the PBKDF algorithm is analyzed through the game-playing approach and upper bounded of the Adversarys Advantage over the KDF and random function. Based on that, we discussed the practical safety of the Office encrypted files, and show that Office is secure when the user password is longer than 6 characters.

The experimental blind timing acquisition scheme for FM-DCSK communication system

System design and performance are presented for an experimental FM-DCSK radio system with a blind timing acquisition scheme. The transmitter and receiver architecture is proposed, and a novel two-stage blind bit synchronization algorithm for a fast and efficient timing acquisition process is introduced. This synchronization scheme exploits the waveform repetition pattern which naturally present in the DCSK transmitted reference signal structure. The BER performance of such systems is evaluated under AWGN and multi-path channel, the value is fairly close to that of perfect synchronization, which is 0.2dB difference at SNR 10–15dB. Key building blocks of circuit implementation are also presented.