Results 1 - 10 of 1180
Results 1 - 10 of 1180. Search took: 0.025 seconds
|Sort by: date | relevance|
[en] We analyze the security of a quantum secure direct communication and authentication protocol based on single photons. We first give an impersonation attack on the protocol. The cryptanalysis shows that there is a gap in the authentication procedure of the protocol so that an opponent can reveal the secret information by an undetectable attempt. We then propose an improvement for the protocol and show it closes the gap by applying a mutual authentication procedure. In the improved protocol single photons are transmitted once in a session, so it is easy to implement as the primary protocol. Furthermore, we use a novel technique for secret order rearrangement of photons by which not only quantum storage is eliminated also a secret key can be reused securely. So the new protocol is applicable in practical approaches like embedded system devices.
[en] A UHF RF identification system based on the 0.18 μm CMOS process has been developed for short range and harsh size requirement applications, which is composed of a fully integrated tag and a special reader. The whole tag chip with the antenna takes up an area of 0.36 mm"2, which is smaller than other reported tags with an on-chip antenna (OCA) using the standard CMOS process. A self-defined protocol is proposed to reduce the power consumption, and minimize the size of the tag. The specialized SOC reader system consists of the RF transceiver, digital baseband, MCU and host interface. Its power consumption is about 500 mW. Measurement results show that the system's reading range is 2 mm with 20 dBm reader output power. With an inductive antenna printed on a paper substrate around the OCA tag, the reading range can be extended from several centimeters to meters, depending on the shape and size of the inductive antenna. (paper)
[en] System identification is the art of finding mathematical tools and algorithms that build an appropriate mathematical model of a system from measured input and output data. Hammerstein model, consisting of a memoryless nonlinearity followed by a dynamic linear element, is often a good trade-off as it can represent some dynamic nonlinear systems very accurately, but is nonetheless quite simple. Moreover, the extensive knowledge about LTI system representations can be applied to the dynamic linear block. On the other hand, finding an effective representation for the nonlinearity is an active area of research. Recently, support vector machines (SVMs) and least squares support vector machines (LS-SVMs) have demonstrated powerful abilities in approximating linear and nonlinear functions. In contrast with other approximation methods, SVMs do not require a-priori structural information. Furthermore, there are well established methods with guaranteed convergence (ordinary least squares, quadratic programming) for fitting LS-SVMs and SVMs. The general objective of this research is to develop new subspace algorithms for Hammerstein systems based on SVM regression.
[en] A classical way for the frequency domain identification of systems is applying a sine wave excitation with certain frequency to the input and measuring the output response to excitation using phase sensitive instruments based mostly on Fourier transform. Such a parameter as time is out of scope in this case. Mathematically saying, Fourier transform expects the time interval from minus to plus infinity. In practice, it means that we have to wait until the transient process will be fully over in the system after applying the excitation. Therefore, covering a wide frequency range takes a long time when using frequency stepping or a slow enough sweeping over the whole frequency range. To perform faster measurements, sine wave based chirp pulses with certain duration are proposed for excitation. In this case the sine wave does not has only one certain frequency any more, but its instantaneous angle frequency changes over the required frequency range during the pulse. When the frequency changing (acceleration) is constant, then we have a linear chirp. Linear chirp can cover several decades of frequency with a constant spectral density within the excitation bandwidth. But for shaping of the excitation spectrum, more complicated chirps are introduced. Chirp excitation can contain thousands of cycles, but can be even as short as one quarter of a single cycle. Therefore, we can say that the chirp excitation is scalable in time - we can choose the time interval independently on the frequency bandwidth. On the other hand, we can choose the frequency bandwidth independently on the excitation time. Such the freedom - double scalability in time and frequency - is especially important when time variant dynamic systems (electronic circuits with controllable parameters, beating heart, breathing lungs, working mechanism, ongoing electrochemical reaction) has to be identified. Every special case has its own optimal excitation waveform, which enables to derive the maximum amount of information about the time variant system under study.
[en] Credentials as a means of identifying individuals have traditionally been a photo badge and more recently, the coded credential. Another type of badge, the proximity credential, is making inroads in the personnel identification field. This badge can be read from a distance instead of being veiewed by a guard or inserted into a reading device. This report reviews proximity credentials, identifies the companies marketing or developing proximity credentials, and describes their respective credentials. 3 tabs
[en] We propose a quantum message authentication scheme that provides integrity and origin authentication using a remote state preparation. Authentication is one of the security services that must be provided in secure communication. Quantum message authentication is the base scheme for realizing quantum authentication that is known to be a secure technique even in a forthcoming quantum computer environment. The proposed scheme creates a quantum message authentication code (QMAC) with only a single qubit measurement. It is therefore easy to implement and operate compared to existing technology that normally generates a QMAC with a Bell measurement or controlled unitary operation. For security analysis, we design a quantum random oracle model based on the random oracle model and demonstrate the quantum collision resistance with it. From the analysis, the probability of the quantum collision is 0.69N per qubit, where N is the size of the message sequence. Since the probability of quantum collision in the case of N ≥ 13 becomes extremely low of under 0.8%, we confirm that the proposed scheme guarantees the integrity and origin authentication of the message. (paper)
[en] Identity verification devices based on the interrogation of six different human biometric features or actions now exist and in general have been in development for about ten years. The capability of these devices to meet the cost and operational requirements of speed, accuracy, ease of use and reliability has generally increased although the verifier industry is still immature. Sandia Laboratories makes a continuing effort to stay abreast of identity verifier developments and to assess the capabilities and improvements of each device. Operating environment and procedures more typical of field use can often reveal performance results substantially different from laboratory tests. An evaluation of several recently available verifiers is herein reported
[en] Banknote security is an issue that has led in the last decades to insert, inside the banknote itself, a very high number of controlling methods with the aim of verifying possible tampering attempts. In order to distinguish the false banknotes, sophisticated means (i.e. watermark, feel of the paper, raised print, metallic threads, quality of the printing, holograms, ultraviolet features, micro-lettering, etc) are often used. The purpose of this paper is to show a new approach and related method to protect banknotes and to verify their originality, based on the idea of hylemetry (methodology conceptually similar to biometry) applied to banknotes. Specifically, the hylemetric feature used in this paper is the random distribution pattern of the metallic security fibers set into the paper pulp. The outcome of the proposed solution is to identify an original banknote using a binary sequence derived from the banknote itself
[en] This article presents a proposal of a heat meter and remote meter reading system for the disadvantages of the hackers very easily using eavesdropping, tampering, replay attack of traditional remote meter reading system. The system selects trusted technology such as, the identity authentication, integrity verifying, and data protection. By the experiments, it is proved that the remote meter reading system of the heat meter can be used to verify the feasibility of the technology, and verify the practicability and operability of data protection technology. (paper)
[en] Recently, a new controlled quantum dialogue (CQD) protocol which is secure against the conspiring attack from the users without the controller’s permission was put forward. However, it is found that this CQD protocol is weak against the different initial state (DIS) attack and the denial-of-service (DoS) attack from the dishonest controller. For the DIS attack, the controller prepares different initial states to eavesdrop on the users’ messages. For the DoS attack, the controller deliberately announces the wrong classical information which is used for the users to encode secret messages, and thus, one user gets the wrong message from the other user. To mend the DIS attack, a security check to the controller is added to prevent the dishonest controller from preparing the different initial states. To mend the DoS attack, a message authentication is added to prevent the dishonest controller from publishing the wrong classical information. It shows that the security check to the controller and the message authentication can effectively prevent the DIS attack and the DoS attack from the dishonest controller, respectively.