Data fusion in biometrics

Any biometric system has drawbacks and cannot warranty 100% identification rates, nor 0% false acceptance and rejection ratios. One way to overcome the limitations is through a combination of different biometric systems. In addition, a multimodal biometric recognition is more difficult to fool than a single, biometric system, because it is more unlikely to defeat two or three biometric systems than one. This paper summarizes the different data fusion levels, and how it must be performed in order to improve the results of each combined system on its own     

A low-cost Webcam & personal computer opens doors

Face recognition is one of the most successful ways for biometric recognition. One of its advantages is the high social acceptance by users, because it does not have the criminal stigma associated to other biometric traits, such as fingerprints. In addition, the cost of a webcam can be below 20 USD, which is certainly lower than other biometric acquisition devices. For this reason, the authors have developed a low-cost door-opening system, which is installed in our university premises for lab control access.     

基于小波包的手写体签名特征提取方法

手写体签名识别的很多特征提取方法都是基于经过复杂数据预处理和分割技术的二值图像．并且特征提取过程不可逆。因为复杂的预处理、较大的计算量和签名的连笔现象使得特征提取非常困难并对识别结果产生直接的影响。为了解决以上问题,提出了基于小波包的特征提取方法．．首先在预处理过程中对签名图像进行大小归一化：其次利用小波包对签名图像进行分解以得到签名图像在二维空间上点的集合;然后用这些二维点进行签名识别。本方法的数据预处理简单,避免了复杂分割．特征提取完全可逆。实验结果表明其具有较好的抗噪性、鲁棒性、适应性和识别率,为含噪脱机手写体签名识别提供了一种解决方案。     

Smart card information and operations using biometrics

Nowadays many systems need a portable media to store some sensible data, such as smart cards. The information can be protected by the user with his Personal Identification Number (PIN), or through biometrics. Unfortunately, there is not a smart card today that can verify the biometric template inside it, performing this task in the terminal. The author has developed the algorithms and data structures needed to solve this problem. Therefore, he has created a smart card with user biometric authentication, based on an Open Platform smart card (in this case, a JavaCard). To achieve these results, different biometric techniques have been studied: speaker verification, hand geometry and iris recognition. Experimental results are given to show the viability of the prototype developed     

Iris-based biometric recognition using dyadic wavelet transform

A biometric identification system, based on the processing of the human iris by the dyadic wavelet transform, has been introduced. The procedure to obtain an iris signature of 256 bits has been described, as well as the feature extraction block and the verification system. The results have shown that the system can achieve high rates of security.     

Sequence comparison techniques for multisensor data fusion andtarget recognition

A new class of techniques for multisensor fusion and target recognition is proposed using sequence comparison by dynamic programming and multiple model estimation. The objective is to fuse information on the kinematic state and “nonkinematic” signature of unclassified targets, assessing the joint likelihood of all observed events for recognition. Relationships are shown to previous efforts in pattern recognition and state estimation. This research applies “classical” speech processing-related and other sequence comparison methods to moving target recognition, extends the efforts of previous researchers through improved fusion with kinematic information, relates the proposed techniques to Bayesian theory, and applies parameter identification methods to target recognition for improved understanding of the subject in general. The proposed techniques are evaluated and compared with existing approaches using the method of generalized ambiguity functions, which lends to a form of Cramer-Rao lower bound for target recognition     

空间目标地基光电探测与识别技术的发展

空间目标地基光电探测与识别技术是空间态势感知的主要技术手段之一。首先归纳了空间目标的典型光学特征,分析了用于轨道与光学特征探测与识别的两类光电望远镜特点,梳理了国外空间目标光电探测与识别技术的发展历程,简要总结了空间目标地基光电探测与识别技术和应用需求间的主要问题,展望了空间目标光电探测与识别技术的未来发展方向。     

Radar Signature of a Helicopter Illuminated by a Long LFM Signal

Helicopters exhibit a very particular Doppler radar signature caused by the movement of rotor blades. This signature can easily be derived using a short-time approximation: the blades are assumed to be static during each pulse. In wideband linear frequency modulated (LFM) radars, however, this assumption cannot be made. The work presented here describes the echo of rotary blades illuminated by LFM radars without the short-time assumption and provides useful information for detection and recognition purposes.     

A new approach to automatic target recognition

The fundamental problems of automatic target recognition (ATR) are discussed. A new approach to ATR is suggested that includes: a new method of scoring ATR performance, a new concept of artificial images, a new method called probing for extracting target signature knowledge from image experts, and suggestions for coping with the problem of insufficient test data and algorithm obsolescence     

面向办公自动化的群签名解决方案

随着办公自动化(OA)近年的飞速发展,对于数字签名的要求越来越高,这不仅体现在数字签名的安全程度上,同时也对签名形式的多样性提出了要求。群签名是近年来提出的一种新型签名方案,由于OA系统本身所特有的易于管理,效率高等特点使的该项技术较之在电子商务领域有着更高的可行性,本文论述了利用群签名算法结合证书认证等技术,创建一个针对办公自动化的群签名应用方案。     

等效动压洞壁干扰修正方法的研究与应用

带螺旋桨飞机模型风洞实验进行洞壁干扰修正时,必须考虑螺旋桨滑流的影响。运用等效动压对运八飞机带螺旋桨模型风洞实验才气进行洞壁干扰修正,分析洞壁对带螺旋桨飞机模型试验数据的影响,并与壁压信息修正方法进行了比较。两种修正方法的修正结果基本一致,壁压信息法能实际反映洞壁干扰影响,但壁压信息法需要进行准确的壁压测量,增加实验工作量;等效动压法是以经典的洞壁干扰修正公式为基础,考虑了螺旋桨滑流的影响,而且带     

On the vulnerability of biometric security systems

This paper presents an overview of the weakness of biometric security systems and possible solutions to improve it. Different levels of attack are described, and the strengths and weaknesses of the main biometric system are emphasized. Solutions are provided with special emphasis on cryptography and watermarking techniques.     

Security Technology. The 36th International Carnahan conference on security technology

The following topics are dealt with: security environment; civil force protection; security technologies; transportation; vulnerability analysis; smart cards; biometric identification; human detection; passenger-examining imaging systems; intrusion detection; and hoax detection.     

Multi-aspect radar target recognition method based on scattering centers and HMMs classifiers

A hidden Markov model (HMM)-based method for recognizing aerial targets according to the sequential high-range-resolution (HRR) radar signature is presented. Its recognition features are the location information of scattering centers extracted from the HRR radar echoes by the relax algorithm. The HMM is used to characterize the spatio-temporal information of a target. Several HMMs are cascaded in a chain to model the variation in the target orientation and used as classifiers. Computer simulations with the inverse synthetic aperture radar (ISAR) data are given to demonstrate that for an open-set recognition, average class-recognition rates of 84.50% and 89.88% are achieved, respectively, under two given conditions.     

Fingerprint verification using smart cards for access control systems

Over the past few years, the authors have tried to integrate biometrics into a smart card. In this paper, to improve error rates obtained with hand geometry biometrics and the costs with the iris recognition system, fingerprints are used. This technique, quite well known in the industry and deeply studied for the last century, has improved its electronic sensors, pulling down prices and, therefore, enabling its use in many more applications. The first step, as in every biometric system, is to obtain an image of the user's fingerprint. After this, a pre-processing algorithm is applied, which enables feature extraction to obtain the location and type of all minutiae, i.e., the discontinuities in the ridges and valleys of the fingerprint. Due to the fact that it is not possible to always catch the same number of minutiae, a special matching algorithm should be applied to compare the feature vector with the corresponding user's template. Efforts to integrate this matching algorithm in a low computer power device, such as a smart card, are given, showing the paths that should be followed in order to improve the security of access control and payment systems available today.     

Changes to vascular biometric system security & performance

When considering biometrics for a Personal Identification System, different modalities can be considered. The final selection will depend on specific application requirements. From the several modalities existing nowadays, vascular systems have appeared on the scene lately. Vein-based identification is claimed to be as reliable as fingerprint or iris identification, but with the usability of hand geometry or even the face. As with any other biometric modalities, vascular solutions have to be deeply analyzed for all relevant factors that could affect their performance or the security level achieved. This will show the analysis of the performance and security achieved by a commercial vascular biometric system, when being applied in several real-world scenarios. These scenarios will cover typical office environments to the more extreme environments, such as extreme light and temperatures, as those suffered in a banking ATM, or with high humidity such as in a gym. The results will show the strengths of this modality, as well as those points where further improvements are needed.     

State-of-the-art in speaker recognition

Recent advances in speech technologies have produced new tools that can be used to improve the performance and flexibility of speaker recognition. While there are few degrees of freedom or alternative methods when using fingerprint or iris identification techniques, speech offers much more flexibility and different levels to perform recognition: the system can force the user to speak in a particular manner, different for each attempt to enter. Also, with voice input, the system has other degrees of freedom, such as the use of knowledge/codes that only the user knows, or dialectical/semantical traits that are difficult to forge. This paper offers an overview of the state-of-the-art in speaker recognition, with special emphasis on the pros and cons, and the current research lines. The current research lines include improved classification systems, and the use of high level information by means of probabilistic grammars. In conclusion, speaker recognition is far away from being a technology where all the possibilities have already been explored.     

基于图象处理的QR码识别

随着智能手机技术的发展和二维码技术的推广,QR码的手机识别技术的应用越来越广泛.根据QR条码图像符号的特殊性,针对QR码识别过程中手机图像采集的实际情况,应用并改进多种图像处理的方法,用C语言实现了对QR条码的译码,取得了良好的效果.     

一个证实门限数字签名方案的安全漏洞分析

证实数字签名协议是一种需要签名者、证实者和验证者三方参与的特殊的数字签名方案,除了签名者,其他任何人都不能以签名者的名义产生有效的证实签名;同样除了证实者,其他任何人也不能对签名的有效性作出判断。文献[8]是一个新的证实门限数字签名协议,是秘密共享思想与证实数字签名方案的新结合,但提出的新方案并未满足证实数字签名协议的某些要求,因此存在着安全漏洞;本文对此进行了详尽的分析,指出了其设计不足之处,从而说明新协议并没有实现其预期设计目标。     

Access control system with hand geometry verification and smartcards

An access control system that joins the uniqueness of biometric verification, as well as the storage security and processing capabilities of smart cards, is defined here. The biometric technique chosen has been hand geometry, which is considered to provide low/medium security (there are other much more secure, as fingerprint, iris or retina), to be easy to use, to achieve high acceptance by users, and which performance is given throughout fast processing and medium cost. Also, the small template size needed for each user is positive for storage and processing capabilities required in the system. But the innovation in the system proposed is that the smart card not only stores the user's template, but also performs the verification process with the features set by the terminal to the card. With this improvement, the security of the system has risen because the template is never extracted from the card, avoiding duplication of such sensible data. The specifications for the enrolment process will be presented as well as the applications where this new system is recommended