Bachar El-Hassan

Bio: Bachar El-Hassan is an academic researcher from Lebanese University. The author has contributed to research in topics: Least mean squares filter & Key-agreement protocol. The author has an hindex of 7, co-authored 33 publications receiving 198 citations.

A Fast and Secure Elliptic Curve Based Authenticated Key Agreement Protocol For Low Power Mobile Communications

Abstract: The increasing progress in wireless mobile communication has attracted an important amount of attention on the security issue. To provide secure communication for mobile devices, authenticated key agreement protocol is an important primitive for establishing session key. So far, several protocols have been proposed to provide robust mutual authentication and key establishment for wireless local area network (WLAN). In this paper we present a fast and secure authenticated key agreement (EC-SAKA) protocol based on elliptic curve cryptography. Our proposed protocol provides secure mutual authentication, key establishment and key confirmation over an untrusted network. The new protocol achieves many of the required security and performance properties. It can resist dictionary attacks mounted by either passive or active networks intruders. It can resist Man-In-The Middle attack. It also offers perfect forward secrecy which protects past sessions and passwords against future compromise. In addition, it can resist known- key and resilience to server attack. Our proposed protocol uses ElGamal signature techniques (ECEGS). We show that our protocol meets the above security attributes under the assumption that the elliptic curve discrete logarithm problem is secure. Our proposed protocol offers significantly improved performance in computational and communication load over comparably many authenticated key agreement protocols such as B-SPEKE, SRP, AMP, PAK-RY, PAK-X, SKA, LR-AKE and EC-SRP.

A Secure Authenticated Key Agreement Protocol Based on Elliptic Curve Cryptography

Abstract: To provide secure communication for mobile devices, authenticated key agreement protocol is an important primitive for establishing session key. So far, several protocols have been proposed to provide robust mutual authentication and key establishment for wireless local area network (WLAN). In this paper we present a secure authenticated key agreement (EC-SAKA) protocol based on elliptic curve cryptography. Our proposed protocol provides secure mutual authentication, key establishment and key confirmation over an untrusted network. The new protocol achieves many of the required security and performance properties. It can resist dictionary attacks mounted by either passive or active networks intruders. It can resist man-in-the middle attack. It also offers perfect forward secrecy which protects past sessions and passwords against future compromise. In addition, it can resist known-key and resilience to server attack. Our proposed protocol uses the signature techniques of ECDSA and the authentication protocol SKA concept. We show that our protocol meets the above security attributes under the assumption that the elliptic curve discrete logarithm problem is secure. Our proposed protocol offers significantly improved performance in computational and communication load over comparably many authenticated key agreement protocols such as B-SPEKE, SRP, AMP, PAK-RY, PAK-X, SKA, LR-AKE and EC-SRP.

Multi-User Angle-Domain MIMO-NOMA System for mmWave Communications

Abstract: Thanks to the high directionality of millimeter-wave (mmWave) channels, angle-domain beamforming is an appealing technique for multi-user multiple-input multiple-output (MU-MIMO) in terms of sum-throughput performance and limited feedback. By utilizing only the angular information of users at the transmitter, we propose an angle-domain non-orthogonal multiple access (NOMA) scheme to enhance the sum-throughput of the mmWave MU-MIMO system, especially in congested cells. We first derive a set of angular-based performance metrics, such as the inter-user spatial interference, the user channel quality, and the sum-throughput, by exploiting the specific features of the mmWave propagation. Then, a multi-user clustering algorithm is developed based on the spatial interference metric, and a new user ordering strategy is proposed using the angular-based channel quality metric. Additionally, we design a power allocation method that maximizes the angular-based sum-throughput. Extensive numerical results show that the proposed scheme significantly improves the performance of the mmWave MU-MIMO system by achieving up to 39% increase in the spectral efficiency when the number of users is closed to the number of antennas. Moreover, we find that the proposed user ordering strategy outperforms other limited feedback strategies, and the angular-based power allocation allows for efficient successive interference cancellation.

A Pipelined Reduced Complexity Two-Stages Parallel LMS Structure for Adaptive Beamforming

Abstract: In this paper, we propose a reduced complexity parallel least mean square structure (RC-pLMS) for adaptive beamforming and its pipelined hardware implementation. RC-pLMS is formed by two least mean square (LMS) stages operating in parallel (pLMS), where the overall error signal is derived as a combination of individual stage errors. The pLMS is further simplified to remove the second independent set of weights resulting in a reduced complexity pLMS (RC-pLMS) design. In order to obtain a pipelined hardware architecture of our proposed RC-pLMS algorithm, we applied the delay and sum relaxation technique (DRC-pLMS). Convergence, stability and quantization effect analysis are performed to determine the upper bound of the step size and assess the behavior of the system. Computer simulations demonstrate the outstanding performance of the proposed RC-pLMS in providing accelerated convergence and reduced error floor while preserving a LMS identical $O(N)$ complexity, for an antenna array of $N$ elements. Synthesis and implementation results show that the proposed design achieves a significant increase in the maximum operating frequency over other variants with minimal resource usage. Additionally, the resulting beam radiation pattern show that the finite precision DRC-pLMS implementation presents similar behavior of the infinite precision theoretical results.

Machine learning schemes in augmented reality for features detection

Abstract: Augmented Reality (AR) is a relatively old concept technology, which reached the large public very recently. We can use it to enhance our environments, by augmenting the image, the voice and delivering details and annotations about the surrounding space. Augmented reality (AR) is a growing field, with many diverse applications ranging from TV and film production, to industrial maintenance, medicine, education, entertainment and games. This paper presents an improved approach for image augmented-reality, by acting on two axes in the augmented reality process. First, a machine learning step is added to the detection part. Second, the registration of augmented image is processed by using the following techniques: statistical appearance models, and covariance matrices of dense image descriptors. A tuning of the used techniques and algorithms will be done in order to obtain a reliable and real-time image augmentation. We give a detailed description on how we chose the methods, and we compare our approach with other methods used in this domain. Finally, an evaluation of the proposed technique is presented as well as a performance study for a given use case.

Certificateless Remote Anonymous Authentication Schemes for WirelessBody Area Networks

Abstract: Wireless body area network (WBAN) has been recognized as one of the promising wireless sensor technologies for improving healthcare service, thanks to its capability of seamlessly and continuously exchanging medical information in real time. However, the lack of a clear in-depth defense line in such a new networking paradigm would make its potential users worry about the leakage of their private information, especially to those unauthenticated or even malicious adversaries. In this paper, we present a pair of efficient and light-weight authentication protocols to enable remote WBAN users to anonymously enjoy healthcare service. In particular, our authentication protocols are rooted with a novel certificateless signature (CLS) scheme, which is computational, efficient, and provably secure against existential forgery on adaptively chosen message attack in the random oracle model. Also, our designs ensure that application or service providers have no privilege to disclose the real identities of users. Even the network manager, which serves as private key generator in the authentication protocols, is prevented from impersonating legitimate users. The performance of our designs is evaluated through both theoretic analysis and experimental simulations, and the comparative studies demonstrate that they outperform the existing schemes in terms of better trade-off between desirable security properties and computational overhead, nicely meeting the needs of WBANs.