The Use of EEG Signals For Biometric Person Recognition

This work is devoted to investigating EEG-based biometric recognition systems. One potential advantage of using EEG signals for person recognition is the difficulty in generating artificial signals with biometric characteristics, thus making the spoofing of EEG-based biometric systems a challenging task. However, more works needs to be done to overcome certain drawbacks that currently prevent the adoption of EEG biometrics in real-life scenarios: 1) usually large number of employed sensors, 2) still relatively low recognition rates (compared with some other biometric modalities), 3) the template ageing effect. The existing shortcomings of EEG biometrics and their possible solutions are addressed from three main perspectives in the thesis: pre-processing, feature extraction and pattern classification. In pre-processing, task (stimuli) sensitivity and noise removal are investigated and discussed in separated chapters. For feature extraction, four novel features are proposed; for pattern classification, a new quality filtering method, and a novel instance-based learning algorithm are described in respective chapters. A self-collected database (Mobile Sensor Database) is employed to investigate some important biometric specified effects (e.g. the template ageing effect; using low-cost sensor for recognition). In the research for pre-processing, a training data accumulation scheme is developed, which improves the recognition performance by combining the data of different mental tasks for training; a new wavelet-based de-noising method is developed, its effectiveness in person identification is found to be considerable. Two novel features based on Empirical Mode Decomposition and Hilbert Transform are developed, which provided the best biometric performance amongst all the newly proposed features and other state-of-the-art features reported in the thesis; the other two newly developed wavelet-based features, while having slightly lower recognition accuracies, were computationally more efficient. The quality filtering algorithm is designed to employ the most informative EEG signal segments: experimental results indicate using a small subset of the available data for feature training could receive reasonable improvement in identification rate. The proposed instance-based template reconstruction learning algorithm has shown significant effectiveness when tested using both the publicly available and self-collected databases

On the Usability of Electroencephalographic Signals for Biometric Recognition: A Survey

Research on using electroencephalographic signals for biometric recognition has made considerable progress and is attracting growing attention in recent years. However, the usability aspects of the proposed biometric systems in the literatures have not received significant attention. In this paper, we present a comprehensive survey to examine the development and current status of various aspects of electroencephalography (EEG)-based biometric recognition. We first compare the characteristics of different stimuli that have been used for evoking biometric information bearing EEG signals. This is followed by a survey of the reported features and classifiers employed for EEG biometric recognition. To highlight the usability challenges of using EEG for biometric recognition in real-life scenarios, we propose a novel usability assessment framework which combines a number of user-related factors to evaluate the reported systems. The evaluation scores indicate a pattern of increasing usability, particularly in recent years, of EEG-based biometric systems as efforts have been made to improve the performance of such systems in realistic application scenarios. We also propose how this framework may be extended to take into account Aging effects as more performance data becomes available

Identity Recognition Using Biological Electroencephalogram Sensors

Brain wave signal is a bioelectric phenomenon reflecting activities in human brain. In this paper, we firstly introduce brain wave-based identity recognition techniques and the state-of-the-art work. We then analyze important features of brain wave and present challenges confronted by its applications. Further, we evaluate the security and practicality of using brain wave in identity recognition and anticounterfeiting authentication and describe use cases of several machine learning methods in brain wave signal processing. Afterwards, we survey the critical issues of characteristic extraction, classification, and selection involved in brain wave signal processing. Finally, we propose several brain wave-based identity recognition techniques for further studies and conclude this paper

EEG Biometrics During Sleep and Wakefulness: Performance Optimization and Security Implications

L’internet des objets et les mégadonnées ont un grand choix de domaines d’application. Dans les soins de santé ils ont le potentiel de déclencher les diagnostics à distance et le suivi en temps réel. Les capteurs pour la santé et la télémédecine promettent de fournir un moyen économique et efficace pour décentraliser des hôpitaux en soulageant leur charge. Dans ce type de système, la présence physique n’est pas contrôlée et peut engendrer des fraudes d’identité. Par conséquent, l'identité du patient doit être confirmée avant que n'importe quelle décision médicale ou financière soit prise basée sur les données surveillées. Des méthodes d’identification/authentification traditionnelles, telles que des mots de passe, peuvent être données à quelqu’un d’autre. Et la biométrie basée sur trait, telle que des empreintes digitales, peut ne pas couvrir le traitement entier et mènera à l’utilisation non autorisée post identification/authentification. Un corps naissant de recherche propose l’utilisation d’EEG puisqu’il présente des modèles uniques difficiles à émuler et utiles pour distinguer des sujets. Néanmoins, certains inconvénients doivent être surmontés pour rendre possible son adoption dans la vraie vie : 1) nombre d'électrodes, 2) identification/authentification continue pendant les différentes tâches cognitives et 3) la durée d’entraînement et de test. Pour adresser ces points faibles et leurs solutions possibles ; une perspective d'apprentissage machine a été employée. Premièrement, une base de données brute de 38 sujets aux étapes d'éveil (AWA) et de sommeil (Rem, S1, S2, SWS) a été employée. En effet, l'enregistrement se fait sur chaque sujet à l’aide de 19 électrodes EEG du cuir chevelu et ensuite des techniques de traitement de signal ont été appliquées pour enlever le bruit et faire l’extraction de 20 attribut dans le domaine fréquentiel. Deux ensembles de données supplémentaires ont été créés : SX (tous les stades de sommeil) et ALL (vigilance + tous les stades de sommeil), faisant 7 le nombre d’ensembles de données qui ont été analysés dans cette thèse. En outre, afin de tester les capacités d'identification et d'authentification tous ces ensembles de données ont été divises en les ensembles des Légitimes et des Intrus. Pour déterminer quels sujets devaient appartenir à l’ensemble des Légitimes, un ratio de validation croisée de 90-10% a été évalué avec différentes combinaisons en nombre de sujets. A la fin, un équilibre entre le nombre de sujets et la performance des algorithmes a été trouvé avec 21 sujets avec plus de 44 epochs dans chaque étape. Le reste (16 sujets) appartient à l’ensemble des Intrus.De plus, un ensemble Hold-out (4 epochs enlevées au hasard de chaque sujet dans l’ensemble des Légitimes) a été créé pour évaluer des résultats dans les données qui n'ont été jamais employées pendant l’entraînement.----------ABSTRACT : Internet of Things and Big Data have a variety of application domains. In healthcare they have the potential to give rise to remote health diagnostics and real-time monitoring. Health sensors and telemedicine applications promise to provide and economic and efficient way to ease patients load in hospitals. The lack of physical presence introduces security risks of identity fraud in this type of system. Therefore, patient's identity needs to be confirmed before any medical or financial decision is made based on the monitored data. Traditional identification/authentication methods, such as passwords, can be given to someone else. And trait-based biometrics, such as fingerprints, may not cover the entire treatment and will lead to unauthorized post-identification/authentication use. An emerging body of research proposes the use of EEG as it exhibits unique patterns difficult to emulate and useful to distinguish subjects. However certain drawbacks need to be overcome to make possible the adoption of EEG biometrics in real-life scenarios: 1) number of electrodes, 2) continuous identification/authentication during different brain stimulus and 3) enrollment and identification/authentication duration. To address these shortcomings and their possible solutions; a machine learning perspective has been applied. Firstly, a full night raw database of 38 subjects in wakefulness (AWA) and sleep stages (Rem, S1, S2, SWS) was used. The recording consists of 19 scalp EEG electrodes. Signal pre-processing techniques were applied to remove noise and extract 20 features in the frequency domain. Two additional datasets were created: SX (all sleep stages) and ALL (wakefulness + all sleep stages), making 7 the number of datasets that were analysed in this thesis. Furthermore, in order to test identification/authentication capabilities all these datasets were split in Legitimates and Intruders sets. To determine which subjects were going to belong to the Legitimates set, a 90-10% cross validation ratio was evaluated with different combinations in number of subjects. At the end, a balance between the number of subjects and algorithm performance was found with 21 subjects with over 44 epochs in each stage. The rest (16 subjects) belongs to the Intruders set. Also, a Hold out set (4 randomly removed epochs from each subject in the Legitimate set) was produced to evaluate results in data that has never been used during training

Brainwave-based authentication using features fusion

This article investigates the use of human brainwaves for user authentication. We used data collected from 50 volunteers and leveraged the Support Vector Machine (SVM) as a classification algorithm for the case study. User recognition patterns are taken from a combination of blinking, attention concentration, and picture recognition emotion sequences. These actions impact alpha, beta, gamma, and theta brain waves, which are measured using several electrodes. Ten different electrode placement patterns are explored, with varied positioning on the head. For each placement position, four features are examined, for a total of 40 extracts in the learning model. Features are: 1) spectral information, 2) coherence, 3) mutual correlation coefficient, and 4) mutual information. Each feature type is trained by the SVM algorithm, and the 40 weak classifier candidates. Adaptive Boosting (AdaBoost), a type of machine learning, is then used to generate a robust classifier, which is subsequently used to create a model, and select features, used to accurately identify individuals for authentication purposes. Upon verifying the proposed method using 32 legitimate users and 18 intruders, we obtained an authentication error rate (ERR) of 0.52%, and a classification rate of 99.06%

Brainwave-based authentication using features fusion

This article investigates the use of human brainwaves for user authentication. We used data collected from 50 volunteers and leveraged the Support Vector Machine (SVM) as a classification algorithm for the case study. User recognition patterns are taken from a combination of blinking, attention concentration, and picture recognition emotion sequences. These actions impact alpha, beta, gamma, and theta brain waves, which are measured using several electrodes. Ten different electrode placement patterns are explored, with varied positioning on the head. For each placement position, four features are examined, for a total of 40 extracts in the learning model. Features are: 1) spectral information, 2) coherence, 3) mutual correlation coefficient, and 4) mutual information. Each feature type is trained by the SVM algorithm, and the 40 weak classifier candidates. Adaptive Boosting (AdaBoost), a type of machine learning, is then used to generate a robust classifier, which is subsequently used to create a model, and select features, used to accurately identify individuals for authentication purposes. Upon verifying the proposed method using 32 legitimate users and 18 intruders, we obtained an authentication error rate (ERR) of 0.52%, and a classification rate of 99.06%

An Electroencephalogram (EEG) Based Biometrics Investigation for Authentication: A Human-Computer Interaction (HCI) Approach

Encephalogram (EEG) devices are one of the active research areas in human-computer interaction (HCI). They provide a unique brain-machine interface (BMI) for interacting with a growing number of applications. EEG devices interface with computational systems, including traditional desktop computers and more recently mobile devices. These computational systems can be targeted by malicious users. There is clearly an opportunity to leverage EEG capabilities for increasing the efficiency of access control mechanisms, which are the first line of defense in any computational system. Access control mechanisms rely on a number of authenticators, including “what you know”, “what you have”, and “what you are”. The “what you are” authenticator, formally known as a biometrics authenticator, is increasingly gaining acceptance. It uses an individual’s unique features such as fingerprints and facial images to properly authenticate users. An emerging approach in physiological biometrics is cognitive biometrics, which measures brain’s response to stimuli. These stimuli can be measured by a number of devices, including EEG systems. This work shows an approach to authenticate users interacting with their computational devices through the use of EEG devices. The results demonstrate the feasibility of using a unique hard-to-forge trait as an absolute biometrics authenticator by exploiting the signals generated by different areas of the brain when exposed to visual stimuli. The outcome of this research highlights the importance of the prefrontal cortex and temporal lobes to capture unique responses to images that trigger emotional responses. Additionally, the utilization of logarithmic band power processing combined with LDA as the machine learning algorithm provides higher accuracy when compared against common spatial patterns or windowed means processing in combination with GMM and SVM machine learning algorithms. These results continue to validate the value of logarithmic band power processing and LDA when applied to oscillatory processes