EM alignment using phase for secure embedded systems

If electromagnetic (EM) waves emanating from a wireless device during a cryptographic computation leak sufficient information, it may be possible for an attacker to reconstruct the secret key. Despite the complexities of a Java-based PDA device, this paper presents a new phase based technique for aligning EM frames for subsequent time based DEMA. The proposed technique involves: fast Fourier transform, phase-substitution, inverse fast Fourier transform and time based DEMA. Results are repeatable over several different secret keys. Unlike previous research the new technique does not require perfect alignment of EM frames, and demonstrates robustness in the presence of a complex embedded system (including cache misses, operating system events, etc.) with random delays as well as random operations. This research is important for future wireless and complex embedded systems where security is crucial.     

构筑嵌入式系统的安全屏障

5年前,数十亿嵌入式系统成为了注意的焦点,当时权威人士预测Y2K故障将会扰乱制造、配电、运输、通信、水净化、现金提取、武器系统的正常运作,还将带来其他许多灾难.全球的政府和私营公司花费数千工时和数十亿美元来分析和更新嵌入式固件,以便能避免可能发生的灾难.这些嵌入式设备目前面临新的敌人,来自越来越多的黑客和恐怖分子,他们试图造成类似的危害,强制进行计划外的运作,或提取保密信息.对于任何新的嵌入式系统设计来说,这个新的现实使安全问题成为最优先考虑的事项.     

Breaking two secure communication systems based on chaotic masking

This paper describes the security weakness of two generalized nonlinear state-space observers-based approaches for both chaos synchronization and secure communication, using chaotic masking and chaotic modulation of a Lorenz system. We show that the security is compromised without any knowledge of the chaotic system parameter values and even without knowing the transmitter structure.     

嵌入式操作系统市场巡礼

引言 嵌入式操作系统是开发嵌入式产品的有力工具。随着“后PC时代”的到来,嵌入式计算机产品的开发日渐火爆。在控制领域,随着32位单片机的功耗不断降低,价格不断走低,越来越得到国人的认可。实时多任务的嵌入式操作系统的使用也受到越来越多的重视,嵌入式操作系统的产品与市场也日趋活跃。由于选择什么样的嵌入式操作系统往往发生于产品开发之前,一旦选中某公司的产品,往往会被该产品“牵着往前走”。故做决定之前不妨多做一些调     

A secure search protocol for lightweight and low-cost RFID systems

In radio frequency identification (RFID) systems, search protocols are used to find a specific item in a large number of tagged products. These protocols should be secure against RFID attacks such as traceability, impersonation, DoS and eavesdropping. Sundaresan et al. (IEEE Trans Dependable Secure Comput, 2015) presented a server-less search protocol based on 128-bits PRNG function and claimed that their method can address all vulnerabilities of previous protocols. In this paper, we prove that Sundaresan et al.’s protocol is vulnerable to traceability attack with the high probability. In addition, we present an improved protocol to solve the proposed problem and analyze its security level informally and formally based on AVISPA tool and BAN logic.     

Improved masking algorithm for chaotic communications systems

A method is proposed for robust synchronisation of the transmitter and receiver in chaotic communications schemes. It is verified in a modified Lorenz system. Simulations and theoretical analysis show that synchronisation robustness greatly improves under the method. Multiple chaotic systems communicating through a single channel can also be synchronised. Synchronisation of each user is independent, allowing multiple access chaotic communications     

嵌入式处理器的快响应安全启动机制探究

基于多粒度储存器运算机制（MMH）,提出了嵌入式系统的快响应安全启动机制(FSBM);根据不同的监控对象,采用不同的策略对存储的信息和外部设计进行监控和保护。利用Xilinx的ML510FPGA开发板,对FSBM进行了设计与实现。实验结果表明： FSBM安全响应机制在安全启动系统的前提下,可以大幅度节约响应时间,提高系统的性能。     

嵌入式处理器的快响应安全启动机制探究

基于多粒度储存器运算机制（MMH）,提出了嵌入式系统的快响应安全启动机制（FSBM）;根据不同的监控对象,采用不同的策略对存储的信息和外部设计进行监控和保护。利用Xilinx的ML510FPGA开发板,对FSBM进行了设计与实现。实验结果表明： FSBM安全响应机制在安全启动系统的前提下,可以大幅度节约响应时间,提高系统的性能。     

A fast-transient high-PSR output-capacitor-free low-dropout regulator for low-power embedded systems

A low-power fast-transient output-capacitor-free low-dropout regulator (LDO) with high power-supply rejection (PSR) is presented in this paper. The proposed LDO utilizes a non-symmetrical class-AB amplifier as the input stage to improve the transient performances. Meanwhile, PSR enhancement circuit, which only consumes 0.2-µA quiescent current at light load, is utilized to form a feedforward cancellation path for improving PSR over wide frequency range. The LDO has been designed and simulated in a mixed signal 0.13-µm CMOS process. From the post simulation results, the LDO is capable of delivering 100-mA output current at 0.2-V dropout voltage, with 3.8-µA quiescent current at light load. The undershoot, the overshoot and the 1 % settling time of the proposed LDO with load current switching from 50 µA to 100 mA in 300 ns are about 100 mV, 100 mV and 1 µs, respectively. With the help of proposed PSR enhancement technique, the LDO achieves a PSR of ?69 dB at 100 kHz frequency for a 100-mA load current.     

Observer-based method for secure communication of chaotic systems

An application of chaotic systems in secure communication is described. In which an observer is used to achieve synchronisation between the encrypter and the decrypter. A major advantage is that the proposed method can be applied to all kinds of chaotic systems. For illustration, text and sound messages are transmitted     

Configuration compression for FPGA-based embedded systems

Field programmable gate arrays (FPGAs) are a promising technology for developing high-performance embedded systems. The density and performance of FPGAs have drastically improved over the past few years. Consequently, the size of the configuration bit-streams has also increased considerably. As a result, the cost-effectiveness of FPGA-based embedded systems is significantly affected by the memory required for storing various FPGA configurations. This paper proposes a novel compression technique that reduces the memory required for storing FPGA configurations and results in high decompression efficiency. Decompression efficiency corresponds to the decompression hardware cost as well as the decompression rate. The proposed technique is applicable to any SRAM-based FPGA device since configuration bit-streams are processed as raw data. The required decompression hardware is simple and the decompression rate scales with the speed of the memory used for storing the configuration bit-streams. Moreover, the time to configure the device is not affected by our compression technique. Using our technique, we demonstrate up to 41% savings in memory for configuration bit-streams of several real-world applications.     

信息系统的安全访问机制

随着我国社会信息化进程的发展,计算机网络及信息系统在各行各业的运作中发挥着越来越重要的作用。然而,由于信息系统本身的脆弱性和日益呈现出的复杂性,信息安全问题不断暴露。本文着重讨论了安全信息系统的BLP多级安全保密模型及其实现机制。     

基于混沌掩盖改进方案的保密通信系统的电路实现

根据Milanovic V和Zaghloul M.E提出的混沌掩盖改进方案,基于具有典型参数的Lorenz混沌系统,用模拟电子电路实现了信号的保密通信.理论分析、EWB仿真和实验结果证明了该方案的有效性.     

Design of a memristor-based look-up table (LUT) for low-energy operation of FPGAs

This paper presents a scheme for designing a memristor-based look-up table (LUT) in which the memristors are connected in rows and columns. As the columns are isolated, the states of the unselected memristors in the proposed scheme are not affected by the WRITE/READ operations; therefore, the prevalent problems associated with nanocrossbars (such as the write half-select and the sneak path currents) are not encountered. Extensive simulation results of the proposed scheme are presented with respect to the WRITE and READ operations; its performance is compared with previous LUT schemes using memristors as well as SRAMs. It is shown that the proposed scheme is significantly better in terms of WRITE time and energy dissipation for both memory operations (i.e. WRITE and READ); moreover it is shown that the READ delay is nearly independent of the LUT dimension. Simulation using benchmark circuits for FPGA implementation show that the proposed LUT offers significant improvements also at this level.     

A secure authentication with key agreement scheme using ECC for satellite communication systems

Recently, Liu et al came up with an authentication with key agreement scheme for securing communication over the low‐earth‐orbit satellite communication systems. However, this paper demonstrates that this scheme cannot provide perfect forward secrecy or defend against the smart card stolen attack, and has some very bad design defects, making it unpractical. Thus, to design a truly secure authentication scheme for satellite communication systems, this paper presents a new scheme, making use of the advantages of elliptic curve cryptography and symmetric cryptography. The security analyses by the widely used BAN logic and heuristic discussions demonstrate that our new scheme possesses perfect security properties and can defend against various well‐known malicious attacks. Moreover, our new scheme allows users to update passwords locally in accordance with their wishes, achieving a good user experience.     

Highly configurable platforms for embedded computing systems

Platform chips, which are pre-designed chips possessing numerous processors, memories, coprocessors, and field-programmable gates arrays, are becoming increasingly popular. Platforms eliminate the costs and risks associated with creating customized chips, but with the drawbacks of poorer performance and energy consumption. Making platforms highly configurable, so they can be tuned to the particular applications that will execute on those platforms, can help reduce those drawbacks. We discuss the trends leading embedded system designers towards the use of platforms instead of customized chips. We discuss UCR research in designing highly configurable platforms, highlighting some of our work in highly configurable caches, and in hardware/software partitioning.