Both ChaCha and AES are standardized as symmetric ciphers in TLS 1.3; AES is a block cipher, whereas ChaCha is a stream cipher. The security of AES has been studied by many researchers. ChaCha, however, needs more security analysis because it has been proposed more recently, compared with AES. Furthermore, ChaCha is improved from Salsa from the point of view of diffusion and thus, diffusion analysis of Salsa and ChaCha is important to understand their security-design criteria. In this study, we revisit diffusion analysis and investigate weak bits and weak columns of Salsa and ChaCha. To the authors'knowledge, this is the first detailed diffusion analysis of Salsa and ChaCha.

Neurologic examination procedures require not only abundant knowledge but also prominent skills. During medical education and training, several methods will be put to use such as watching video, reading books, making use of the simulated patient (SP), and so on. These can help medical staffs, especially novices, to master the skills and accumulate experiences. To make up for the drawbacks of the above methods, such as lack of active interactions, limitation of multi-symptom reproductions, etc, the medical training simulators have been developed to improve training effectiveness. However, most of these simulators only mimic the symptoms. They have no the abilities to show the pathology of diseases. This limits the training effectiveness. In this paper, we propose an elbow robot named WKE-1(Waseda Kyotokagaku Elbow Robot No.1) for neurologic examination training as one part of the whole body patient robot named WKP (Waseda Kyotokagaku Patient). In this robot, we simulate various symptoms occurring during the examination of elbow force, biceps tendon reflex, involuntary action, and also make a physiological neurological model to simulate the pathology of the nervous system. Taking advantage of this robot, the trainee can get a systematic training on both the skills and knowledge. Finally, we take a set of experiments to verify our proposed mechanism and system. The experimental results lead to the consideration that the approach is worth following in further research.

Neurologic examination takes an important role in diagnosis of the nerve system diseases. Neurologic medical staffs, especially the novices, need to be trained on this skill. There are many methodologies which can help to accumulate experiences, such as watching video, reading books, making use of the simulated patient (SP), and so on. However, the best way is to practice on the real patient. All the above methods have their own drawbacks such as lack of active interactions, limitation of multi-symptoms' reproducing, etc. To improve the training effectiveness, an arm robot is proposed in this paper for neurologic examination training as one part of the whole body patient robot named Waseda Kyotokagaku Patient (WKP). In this robot, various symptoms of the elbow force, biceps tendon reflex, involuntary action, and so on, are simulated and shown to the trainee. Finally, a set of experiments was carried out to verify our proposed mechanism and control system. Three neurologists with over 30 years' experience were invited to show their opinions on the reproductions of patients' symptoms, and to discuss the results. The effectiveness of this system was confirmed. The experimental results lead to the consideration that the approach is worth following in further research.

This paper studies dynamics of a simple chaotic spiking oscillator having piecewise constant characteristics. The state variable can vibrate and is reset to the base level just after it reaches the threshold. Repeating this vibrate-and-fire behavior, rich chaotic spike-trains can be generated. Since the solution and return map are piecewise linear, precise analysis is possible. We have investigated characteristics of inter-spike intervals (ISIs) and have found interesting properties: ”The system can output chaotic spike-trains characterized by line-like spectrums of ISIs. Such phenomena and chaos with continuous spectrum appear alternately and make window-like structure in the parameter space. The continuous spectrum of chaos can have wider-band than other types of spiking oscillators.” Presenting a simple electric circuit, typical phenomena are confirmed experimentally.

This paper studies the rotation map with a controlling segment. As the segment varies, the map exhibits superstable periodic orbits, chaos and related bifurcation. The map is applicable to an A/D converter having efficient resolution characteristics. We then present a circuit model of the A/D converter based on spiking neuron and rate-coding. Presenting a test circuit, basic operation is confirmed experimentally.

This paper studies superstable phenomena in a simple circuit consisting of two capacitors, two signum voltage-controlled current sources and one time-controlled impulsive switch. The circuit equation defines piecewise constant vector field, the trajectory is piecewise linear, and the embedded return map is piecewise linear: it is well suited for precise analysis. In some parameter range the map has infinite extrema and one flat segment. In this case the circuit exhibits extremely complicated periodic orbits characterized by superstability for initial value, very fast transient and sensitivity for parameters

This paper describes a design approach to include and optimize Java based cryptographic applications into resource limited embedded devices. For easy prototyping and to be platform independent, the security applications are first developed in Java. Two Java cryptographic libraries, the Bouncy Castle API and the IAIK API are ported to a real embedded device for cost and performance evaluation. It requires 0.88Mbytes to 1.2Mbytes in the KVM footprint size and a few milliseconds to run secret key algorithms and message digests on a typical embedded device. In a second step, the performance critical components of the security applications are moved to hardware acceleration units. The GEZEL design environment is used for the hardware modeling and the co-simulation between software on KVM and the hardware co-processor. Moving the AES algorithm from the SH3-DSP microprocessor to a hardware co-processor shows a performance gain of 10.4x including the overhead in Java, C, and hardware interfaces. Then in a third step, the security critical components are realized by means of a special dynamic differential logic (DDL) style, which makes the secure modules resistant against side channel attacks. All key related actions and cryptographic algorithms are restricted to the secure co-processor. The overall performance gain is 25x compared to a pure Java implementation. Copyright 2004 ACM.