Xidian University

About: Xidian University is a education organization based out in Xi'an, China. It is known for research contribution in the topics: Antenna (radio) & Computer science. The organization has 32099 authors who have published 38961 publications receiving 431820 citations. The organization is also known as: University of Electronic Science and Technology at Xi'an & Xīān Diànzǐ Kējì Dàxué.

A privacy preserving three-factor authentication protocol for e-Health clouds

Abstract: E-Health clouds are gaining increasing popularity by facilitating the storage and sharing of big data in healthcare. However, such an adoption also brings about a series of challenges, especially, how to ensure the security and privacy of highly sensitive health data. Among them, one of the major issues is authentication, which ensures that sensitive medical data in the cloud are not available to illegal users. Three-factor authentication combining password, smart card and biometrics perfectly matches this requirement by providing high security strength. Recently, Wu et al. proposed a three-factor authentication protocol based on elliptic curve cryptosystem which attempts to fulfill three-factor security and resist various existing attacks, providing many advantages over existing schemes. However, we first show that their scheme is susceptible to user impersonation attack in the registration phase. In addition, their scheme is also vulnerable to offline password guessing attack in the login and password change phase, under the condition that the mobile device is lost or stolen. Furthermore, it fails to provide user revocation when the mobile device is lost or stolen. To remedy these flaws, we put forward a robust three-factor authentication protocol, which not only guards various known attacks, but also provides more desired security properties. We demonstrate that our scheme provides mutual authentication using the Burrows---Abadi---Needham logic.

Novel Planar UWB Monopole Antenna With Triple Band-Notched Characteristics

Abstract: A novel spade-shaped ultrawideband (UWB) printed planar monopole antenna with triple band-notched characteristics is proposed. By employing a hook-shaped defected ground structure (DGS) in each side of the ground plane, embedding an Omega-shaped slot on the radiating patch as well as adding a semi-octagon-shaped resonant ring on the back side of the antenna, triple notched frequency bands are achieved. The proposed antenna has been successfully simulated, fabricated, and measured. Effects of the key parameters on the frequency ranges of the notched bands are also investigated. The measured impedance bandwidth defined by VS WR < 2 of 10.1 GHz (2.9-13 GHz), with the triple notched bands of 3.3-3.9, 5.2-5.35, and 5.8-6.0 GHz, is obtained. Measured group delay and transmission characteristics indicate that the antenna has good transient response. Furthermore, the proposed antenna shows the merit of insensitivity to both finite ground size and fabrication tolerances.

New field of cryptography: DNA cryptography

Abstract: DNA cryptography is a new born cryp- tographic field emerged with the research of DNA computing, in which DNA is used as information car- rier and the modern biological technology is used as implementation tool. The vast parallelism and ex- traordinary information density inherent in DNA molecules are explored for cryptographic purposes such as encryption, authentication, signature, and so on. In this paper, we briefly introduce the biological background of DNA cryptography and the principle of DNA computing, summarize the progress of DNA cryptographic research and several key problems, discuss the trend of DNA cryptography, and compare the status, security and application fields of DNA cryptography with those of traditional cryptography and quantum cryptography. It is pointed out that all the three kinds of cryptography have their own ad- vantages and disadvantages and complement each other in future practical application. The current main difficulties of DNA cryptography are the absence of effective secure theory and simple realizable method. The main goal of the research of DNA cryptography is exploring characteristics of DNA molecule and reac- tion, establishing corresponding theories, discovering possible development directions, searching for sim- ple methods of realizing DNA cryptography, and lay- ing the basis for future development.

Lossless Data Embedding Using Generalized Statistical Quantity Histogram

Abstract: Histogram-based lossless data embedding (LDE) has been recognized as an effective and efficient way for copyright protection of multimedia. Recently, a LDE method using the statistical quantity histogram has achieved good performance, which utilizes the similarity of the arithmetic average of difference histogram (AADH) to reduce the diversity of images and ensure the stable performance of LDE. However, this method is strongly dependent on some assumptions, which limits its applications in practice. In addition, the capacities of the images with the flat AADH, e.g., texture images, are a little bit low. For this purpose, we develop a novel framework for LDE by incorporating the merits from the generalized statistical quantity histogram (GSQH) and the histogram-based embedding. Algorithmically, we design the GSQH driven LDE framework carefully so that it: (1) utilizes the similarity and sparsity of GSQH to construct an efficient embedding carrier, leading to a general and stable framework; (2) is widely adaptable for different kinds of images, due to the usage of the divide-and-conquer strategy; (3) is scalable for different capacity requirements and avoids the capacity problems caused by the flat histogram distribution; (4) is conditionally robust against JPEG compression under a suitable scale factor; and (5) is secure for copyright protection because of the safe storage and transmission of side information. Thorough experiments over three kinds of images demonstrate the effectiveness of the proposed framework.