Signature Verification Algorithm Research Articles

An Automatic Signature Verification Algorithm for Smart Devices

In this paper, we propose a stable automatic signature verification algorithm applicable to various smart devices. The proposed algorithm uses real and forgery data all together, which can improve the verification rate dramatically. As a tool for signature acquisition in a smart device, two applications, one using touch with a finger and the other using a pressure-sensing-stylus pen, are developed. The verification core is based on SVM and some modifications are made to include the characteristics of signatures. As shown in experimental results, the minimum error rate was 1.84% in the SVM based method, which can easily defeat 4.38% error rate with the previous parametric approach. Even more, 2.43% error rate was achieved with the features excluding pressure-related features, better than the previous approach including pressure-related features and only about 0.6% more error than the best result, which means that the proposed algorithm can be applied to a smart device with or without pressure-sensing-stylus pens and used for security purposes.

Signature verification: A comprehensive study of the hidden signature method

Abstract Many handwritten signature verification algorithms have been developed in order to distinguish between genuine signatures and forgeries. An important group of these methods is based on dynamic time warping (DTW). Traditional use of DTW for signature verification consists in forming a misalignment score between the verified signature and a set of template signatures. The right selection of template signatures has a big impact on that verification. In this article, we describe our proposition for replacing the template signatures with the hidden signature-an artificial signature which is created by minimizing the mean misalignment between itself and the signatures from the enrollment set. We present a few hidden signature estimation methods together with their comprehensive comparison. The hidden signature opens a number of new possibilities for signature analysis. We apply statistical properties of the hidden signature to normalize the error signal of the verified signature and to use the misalignment on the normalized errors as a verification basis. A result, we achieve satisfying error rates that allow creating an on-line system, ready for operating in a real-world environment

LIVE: Lightweight Integrity Verification and Content Access Control for Named Data Networking

Named data networking (NDN) is a new paradigm for the future Internet wherein interest and data packets carry content names rather than the current IP paradigm of source and destination addresses. Security is built into NDN by embedding a public key signature in each data packet to enable verification of authenticity and integrity of the content. However, existing heavyweight signature generation and verification algorithms prevent universal integrity verification among NDN nodes, which may result in content pollution and denial of service attacks. Furthermore, caching and location-independent content access disables the capability of a content provider to control content access, e.g., who can cache a content and which end user or device can access it. We propose a lightweight integrity verification (LIVE) architecture, an extension to the NDN protocol, to address these two issues seamlessly. LIVE enables universal content signature verification in NDN with lightweight signature generation and verification algorithms. Furthermore, it allows a content provider to control content access in NDN nodes by selectively distributing integrity verification tokens to authorized nodes. We evaluate the effectiveness of LIVE with open source CCNx project. Our paper shows that LIVE only incurs average 10% delay in accessing contents. Compared with traditional public key signature schemes, the verification delay is reduced by over 20 times in LIVE.

An efficient batch verification system and its effect in a real time VANET environment

ABSTRACTVehicle ad hoc network (VANET) provides communication between vehicles and vehicle‐to‐infrastructure communication. High mobility, high speed of vehicles, fast topology changes, and sheer scale are some characteristics that establish VANET as an intensive research topic different from other types of mobile ad hoc network. In this paper, we improve an existing batch verification system on ID‐based group signature and also compare the performance achieved. Then, we analyze the best possible value of the number of signatures to batch at a time for large‐scale VANET. In addition, we introduce a scheduling algorithm for signature verification where batch verification cannot be implemented efficiently. Copyright © 2014 John Wiley & Sons, Ltd.

Authentication using Secure Node Signature Verification Algorithm with Quantum Cryptography

In now a days, most of the communication takes place through Internet. Most of the users are used to transmit their information through insecure channels that are interconnected throughout world. Thus, security must be provided to achieve confidentiality, access control, integrity and authentication. To ensure all these services, various cryptography and steganography techniques like RSA, AES, MD5 and RC5 have been used. Even though, cryptanalysts reinforcing it using some mathematical computation and misused information. Currently, quantum computers have been used to increase the speed of computation and to provide more security for data. It exploits quantum mechanics to provide secure communication. Quantum cryptography (QC) technique has been used to share the key among the participants who wish to share the data. This paper discusses various cryptographic key distribution protocols and quantum mechanics. In this paper we proposed “Secure Node Signature Verification Algorithm”(SNSVA) based on Quantum cryptography technique that describes how authentication can be verified with network nodes. In addition, it explains an approach to improve the performance of cryptography technique. General Terms Sharing, Intrude, Securing, Sender, Receiver, Transceiver, information.

A new strong multiple designated verifiers signature

A Strong Multiple Designated Verifiers Signature (SMDVS) enables a signer to convince a set of verifiers by generating one signature, of which the verification needs the private key of a verifier. After a brief survey of the current SMDVS schemes and attacks, we found that there were reported or applicable attacks on many schemes, and some schemes needed group communications in the signature verification algorithm. We propose a new SMDVS scheme which is secure against current attacks and needs no extra group communications in the verification algorithm. The scheme is proven secure in the random oracle model.

A 2-MAKE: An efficient anonymous and accountable mutual authentication and key agreement protocol for WMNs

Multi-hop hybrid wireless mesh networks (WMNs) have recently attracted increasing attention and deployment. For easy acceptance and wide deployment of WMNs, security, privacy, and accountability issues have to be addressed by providing efficient, reliable, and scalable protocols. The fact that regular users, which may be resource-constrained wireless devices, are involved in routing activities highlights the need for efficiency and compactness. However, the said objectives, i.e., security, privacy, accountability, efficiency etc., are, most of the time, not compatible. So far no previous work has adequately reconciled these conflicting objectives in a practical framework. In this paper, we design and implement such a framework named as A 2-MAKE, which is a collection of protocols. The framework provides an anonymous mutual authentication protocol whereby legitimate users can connect to network from anywhere without being identified or tracked unwillingly. No single party (or authority, network operator, etc.) can violate the privacy of a user, which is provided in our framework in the strongest sense. Our framework utilizes group signatures, where the private keys and corresponding credentials of the users are generated in a secure three-party protocol. User accountability is implemented via user identification and revocation protocols that can be executed by two semi-trusted authorities, one of which is the network operator. The assumptions about the trust level of the network operator are relaxed with respect to similar protocols. Our framework makes use of more efficient signature generation and verification algorithms in terms of computational complexity than their counterparts in literature, where signature size is almost the same as the shortest signatures proposed for similar purposes so far.

Enhanced Cancelable Biometrics for Online Signature Verification

Cancelable approaches for biometric person authentication have been studied to protect enrolled biometric data, and several algorithms have been proposed. One drawback of cancelable approaches is that the performance is inferior to that of non-cancelable approaches. In this paper, we propose a scheme to improve the performance of a cancelable approach for online signature verification. Our scheme generates two cancelable dataset from one raw dataset and uses them for verification. Preliminary experiments were performed using a distance-based online signature verification algorithm. The experimental results show that our proposed scheme is promising.

The algorithm of online handwritten signature verification based on improved DTW

Online handwritten signature verification is widely used because of its celerity and convenience. It is the personal verification based on biometrics technology. It is the verification using information about the movement during writing signature, so it becomes an accepted method of personal verification. Basing on this thesis, an online handwritten signature verification algorithm using improved DTW is presented. The weak point of classic DTW is that only the data points by warping the x-axis are considered but the differences on y-axis of two series are not considered. The two situations above are considered in the improved DTW method in order to prevent this problem and the distance measure of DTW is modified based on improved DTW in this paper particularly. The result of experiment proves that this algorithm obtains a good verification effect.

Hill-Climbing Attacks and Robust Online Signature Verification Algorithm against Hill-Climbing Attacks

Attacks using hill-climbing methods have been reported as a vulnerability of biometric authentication systems. In this paper, we propose a robust online signature verification algorithm against such attacks. Specifically, the attack considered in this paper is a hill-climbing forged data attack. Artificial forgeries are generated offline by using the hill-climbing method, and the forgeries are input to a target system to be attacked. In this paper, we analyze the menace of hill-climbing forged data attacks using six types of hill-climbing forged data and propose a robust algorithm by incorporating the hill-climbing method into an online signature verification algorithm. Experiments to evaluate the proposed system were performed using a public online signature database. The proposed algorithm showed improved performance against this kind of attack.

Dynamic Structural Statistical Model Based Online Signature Verification

In this article, a new dynamic structural statistical model based online signature verification algorithm is proposed, in which a method for statistical modeling the signature’s characteristic points is presented. Dynamic time warping is utilized to match two signature sequences so that correspondent characteristic point pair can be extracted from the matching result. Variations of a characteristic point are described by a multi-variable statistical probability distribution. Three methods for estimating the statistical distribution parameters are investigated. With this dynamic structural statistical model, a discriminant function can be derived to judges a signature to be genuine or forgery at the criterion of minimum potential risk. The proposed method takes advantage of both structure matching and statistical analysis. Tested in two signature databases, the proposed algorithm got much better signature verification performance than other results.

Secure Software Flashing

An increasing number of vehicular electronic control units (ECU) are equipped with reprogrammable flash memory. The software program in the flash memory determines the behavior of the ECU. The program code usually can be updated via a bootloader, e.g., for a firmware update, a bug fix, or an update enabling additional functionality. The download might be performed over a diagnostic channel or in the future increasingly through wireless channels, e.g. Bluetooth or GSM connection. Once such communication channels are opened to the outside world for downloading software, the authenticity of the software must be ensured. An example of a malicious software download is the replacement of firmware by an unauthorized party, e.g., as is done on a large scale through chip tuning in vehicles. In order to control software updates, digital signatures play a central role. Here, a digital signature is generated in a secure back end, e.g. by the automobile manufacturer, and then attached to the new firmware as a cryptographic checksum. The ECU is now able to verify the authenticity of the new firmware by checking the authenticity of the signature. Only if the verification is successful is the new firmware actually run by the device. A proper signature verification algorithm is RSA with a short exponent that can be executed in a few milliseconds on an ARM-class CPU if implemented carefully. Provision of a digital signature algorithm itself is often not the main problem, but its integration into the ECU and adapting the organizational processes are. Certainly a secure software download is only useful if there are neither hidden access points to the firmware (e.g., an enabled debug interface) nor a flawed implementation that allows illegal access. Hence a very careful design and implementation phase has to be performed in addition to the secure software download to make sure that only the defined access path is given. INTRODUCTION Today's vehicles have several dozen electronic control units (ECUs) that control almost everything, such as air conditioning, electric windows, the engine, and the brake system. Several of these ECUs allow downloading of updated program and data code via a boot loader. Such software might be a control unit firmware update for fixing bugs, for improving features, or for downloading data such as additional multimedia files. The first case is also called a software download or simply flashing (since flash memory is updated). The download might be performed over a diagnostic channel or another available communication channel such as Bluetooth and GSM. Once such vehicle communication channels are opened to the outside world for downloading software, their integrity must be ensured. An example of a malicious software download is the replacement of firmware by an unauthorized party, e.g., as done for chip tuning. The main security objective is as follows: 1. Only original software must be accepted by the vehicle: No manipulated or malicious software may be downloaded to the ECU. In particular, software must not be successfully downloaded to the ECU that alters the defined behavior of the vehicle. 2. Only authenticated parties may alter data, e.g., parameters, stored in the ECU. Furthermore, the following is desired for an actual security design:  The compromise of a single control unit does not affect the entire system, i.e., a successful attack does not scale.  The required computational performance on the control unit side shall be minimal.

Handwritten signature verification based on code representation

A method to obtain a code representation of handwritten signatures is described and an algorithm for signature verification based on such representations is proposed. Results of tests to determine efficient methods of image compression for the purpose of signature verification are presented.

A new algorithm for on-line handwriting signature verification based on evolutionary computation

The paper proposes an on-line signature verification algorithm, through which test sample and template signatures can be optimizedly matched, based on evolutionary computation (EC). Firstly, the similarity of signature curve segment is defined, and shift and scale transforms are also introduced due to the randoness of on-line signature. Secondly, this paper puts forward signature verification matching algorithm after establishment of the mathematical model. Thirdly, the concrete realization of the algorithm based on EC is discussed as well. In addition, the influence of shift and scale on the matching result is fully considered in the algorithm. Finally, a computation example is given, and the matching results between the test sample curve and the template signature curve are analyzed in detail. The preliminary experiments reveal that the type of signature verification problem can be solved by EC.

A Markov Chain Monte Carlo Algorithm for Bayesian Dynamic Signature Verification

Authentication of handwritten signatures is becoming increasingly important. With a rapid increase in the number of people who access Tablet PCs and PDAs, online signature verification is one of the most promising techniques for signature verification. This paper proposes a new algorithm that performs a Monte Carlo based Bayesian scheme for online signature verification. The new algorithm consists of a learning phase and a testing phase. In the learning phase, semi-parametric models are trained using the Markov Chain Monte Carlo (MCMC) technique to draw posterior samples of the parameters involved. In the testing phase, these samples are used to evaluate the probability that a signature is genuine. The proposed algorithm achieved an EER of 1.2% against the MCYT signature corpus where random forgeries are used for learning and skilled forgeries are used for evaluation. An experimental result is also reported with skilled forgery data for learning.

Online signature verification using temporal shift estimated by the phase of Gabor filter

A new online signature-verification method using temporal shift estimation is presented. Local temporal shifts existing in signatures are estimated by the differences of the phase outputs of Gabor filter applied to signature signals. In the proposed signature-verification algorithm, an input signature signal undergoes preprocessing procedures including smoothing, size normalization and skew correction, and then its feature profile is extracted from the signature signal. A Gabor filter with the predetermined center frequency /spl omega/ is applied on a feature profile, and a phase profile is computed from the phase output. The feature profile and the phase profile are length normalized and quantized so that a signature code of fixed size is generated. The temporal shifts existing between two signatures are computed by using the differences between the phase profiles. The information about the temporal shifts is used as offsets for comparing the two feature profiles. Therefore, two kinds of dissimilarities are proposed. Temporal dissimilarity is a measure reflecting the amount of total temporal disturbance between the two signatures. The difference between the two signature profiles is computed at each corresponding point pair and is accumulated into temporally arranged feature profile dissimilarity. The decision boundary is represented as a straight line in the dissimilarity space whose two axes are the two dissimilarity measures. The slope and the position of the decision boundary are computed using the distribution of the dissimilarities among the sample signatures involved in the enrollment procedure. The experimental results show that through the compact and fixed size of signature data representation and relatively simple comparison methods, the proposed method can compare signatures 400 times faster than the conventional DP matching based signature-verification method.

OPTIMAL PROTOTYPE FUNCTIONS OF FEATURES FOR ONLINE SIGNATURE VERIFICATION

It is well known that the approach of functions of time to represent the dynamic and static characteristics of signatures usually outperforms the approaches based on parameters; in addition to this result, we propose here that the model or prototype function of the discriminant features of the signatures should be created considering the signature verification problem as a bi-objective optimization problem in which the false acceptance and false rejection rates are minimized simultaneously; to accomplish these goals, a discrete space of solutions is searched by a genetic algorithm, and a continuous space of solutions is searched by a modified gradient method, both spaces containing candidate prototype functions and the one that best meets some optimization criteria is first chosen as the optimal prototype function and then improved. Given that creating the prototype functions of features is just one of the earlier steps of a signature verification system, we also propose here a scheme of signature verification algorithm with intelligent classification. Our approach was tested in the context of random and highly skilled forgeries, with error rates below 0.1% over 7,300 verifications. Our database consisted of 1,762 exemplars, containing genuine signatures and skilled forgeries from 36 persons. Comparison to other methods of making prototype functions of features is shown.

Using geometric extrema for segment-to-segment characteristics comparison in online signature verification

A signature verification algorithm based on a segment-to-segment matching is described, in which a new approach for finding segment-to-segment correspondence is proposed. In the proposed method, geometric extrema are used as segmenting boundaries with two reasons: (1) extrema are reproduced with high stability and (2) the properties of extrema are useful in finding segment-to-segment correspondence. In this paper, a set of rules for legitimate correspondence between extrema is defined based on their properties, which is utilized for the similarity evaluation between segments. Dynamic programming is then applied to find an optimal correspondence map. Through experiments, the proposed algorithm is assessed to be effective in improving discriminative ability. We also showed that the overall performance is further improved by combining the proposed method with the traditional global parametric algorithm.

Stability and style-variation modeling for on-line signature verification

Stability and style variation are important characteristics in handwriting analysis and recognition. This paper describes a stability modeling technique of handwritings in the context of on-line signature verification. With this technique, the stability and style-variation characteristics of the reference samples are deduced from the dynamic warping relationship between the sequences of basic handwriting strokes. Reliability measures of the extracted signature features are incorporated into the signature segmentation, model building, and verification algorithms, so that stable handwriting features are emphasized in the signature matching process, while style variations for less stable features are intentionally tolerated. The generated signature model consists of a structure description graph of the handwriting components and their stability information. A signature is accepted by the model if it is close to a permissible path within the weighted graph. A novel feature of the technique is its ability to refine the correspondence relation of the handwriting during model building and signature verification. This ability enables the verification and partial correction of segmentation errors to reduce the number of false rejections while maintaining the system security level and keeping the number of reference samples manageable.

Off-line arabic signature recognition and verification

Off-line signature recognition and verification is an important part of many business processes. It can be used in many applications such as cheques, certificates, contracts and historical documents. In this paper, a system of two separate phases for signature recognition and verification is developed. A recognition technique is developed based on a multistage classifier and a combination of global and local features. New algorithms for signature verification based on fuzzy concepts are also described and tested. It is concluded from the experimental results that each of the proposed techniques performs well on different counts.