Over the last decade, physical layer secret key generation (PHY-SKG) techniques that exploit reciprocity of wireless channels have attracted considerable interest among researchers in the field of wireless communication. Compared to traditional cryptographic methods, PHY-SKG techniques offer the following advantages: a computationally bounded adversary does not need to be assumed; PHY-SKG avoids the requirement of key management, and secret keys can be dynamically replenished. Additionally, PHY-SKG can enhance existing security schemes because it operates independently of higher layer security schemes. However, a key drawback of PHY-SKG is low secret key generation rate (SKGR), a critical performance metric. Therefore, the role of advanced network technologies (e.g., multiple input multiple output (MIMO) and cooperative MIMO) must be explored to enhance SKGR. This paper describes how MIMO and cooperative MIMO techniques can enhance SKGR.
Over the last decade, physical layer secret key generation (PHY-SKG) techniques that exploit reciprocity of wireless channels have attracted considerable interest among researchers in the field of wireless communication. Compared to traditional cryptographic methods, PHY-SKG techniques offer the following advantages: a computationally bounded adversary does not need to be assumed; PHY-SKG avoids the requirement of key management, and secret keys can be dynamically replenished. Additionally, PHY-SKG can enhance existing security schemes because it operates independently of higher layer security schemes. However, a key drawback of PHY-SKG is low secret key generation rate (SKGR), a critical performance metric. Therefore, the role of advanced network technologies (e.g., multiple input multiple output (MIMO) and cooperative MIMO) must be explored to enhance SKGR. This paper describes how MIMO and cooperative MIMO techniques can enhance SKGR.
Widely recognized security vulnerabilities in current wireless radio access technologies undermine the benefits of ubiquitous mobile connectivity.Security strategies typically rely on bit-level cryptographic techniques and associated protocols at various levels of the data processing stack.These solutions have drawbacks that have slowed down the progress of new wireless services.Physical layer security approaches derived from an information theoretic framework have been recently proposed with secret key generation being the primary focus of this dissertation.Previous studies of physical layer secret key generation (PHY-SKG) indicate that a low secret key generation rate (SKGR) is the primary limitation of this approach.To overcome this drawback, we propose novel SKG schemes to increase the SKGR as well as improve the security strength of generated secret keys by exploiting multiple input and multiple output (MIMO), cooperative MIMO (co-op MIMO) networks.Both theoretical and numerical results indicate that relay-based co-op MIMO schemes, traditionally used to enhance LTE-A network throughput and coverage, can also increase SKGR.Based on the proposed SKG schemes, we introduce innovative power allocation strategies to further enhance SKGR.Results indicate that the proposed power allocation scheme can offer 15% to 30% increase in SKGR relative to MIMO/co-op MIMO networks with equal power allocation at low-power region, thereby improving network security.Although co-op MIMO architecture can offer significant improvements in both performance and security, the concept of joint transmission and reception with relay nodes introduce new vulnerabilities.For example, even if the transmitted information is secured, it is difficult but essential to monitor the behavior of relay nodes.Selfish or malicious intentions of relay nodes may manifest as non-cooperation.Therefore, we propose relay node reliability evaluation schemes to measure and monitor the misbehavior of relay nodes.Using a power-sensing based reliability evaluation scheme, we attempt to detect selfish nodes thereby measuring the level of non-cooperation.An overall node reliability evaluation, which can be used as a guide for mobile users interested in collaboration with relay nodes, is performed at the basestation.For malicious behavior, we propose a network tomography technique to arrive at node reliability metrics.We estimate the delay distribution of each internal link within a co-op MIMO framework and use this estimate as an indicator of reliability.The effectiveness of the proposed node reliability evaluations are demonstrated via both theoretical analysis and simulations results.The proposed PHY-SKG strategies used in conjunction with node reliability evaluation schemes represent a novel cross-layer approach to enhance security of cooperative networks.
Relay nodes (RNs), which are low-power nodes that provide enhanced coverage and capacity at low cost are an integral part of the Long Term Evolution Advanced (LTE-A) standard. In order to boost throughput, cooperative multiple input multiple output (co-op MIMO) techniques are proposed wherein RNs close to end users are recruited to operate as virtual antenna arrays (VAA). In this paper, we exploit the co-op MIMO structure to design and implement a physical layer (PHY-layer) security scheme for LTE-A networks. Specifically, we consider two relay-based co-op MIMO architectures and propose novel secret key generation (SKG) schemes for those cases. Information theoretic results regarding secret key generation rate (SKGR) are presented. Results indicate that relay-based co-op MIMO schemes, traditionally used to enhance LTE-A network throughput and coverage, can also increase SKGR. Our work demonstrates the viability of SKG technique as a potential PHY-layer security scheme for LTE-A networks.
In the rapidly evolving landscape of wireless communication, securing transmitted information remains a critical challenge. This study provides a comprehensive review of secret key generation (SKG) techniques designed to secure physical layer wireless communication channels. We focus on key generation methods that exploit physical layer characteristics such as channel state information, received signal strength, and bit error rate. The computational complexity of these techniques is also examined, emphasizing the trade-offs between security and efficiency for real-world implementations. The review identifies open challenges such as developing low-cost, resource-efficient systems, managing artificial noise, and addressing the impact of mobility and multiuser massive MIMO systems on SKG rates. Our findings aim to guide the development of more efficient, scalable SKG methods for next-generation wireless networks. Additionally, we propose a method for securely generating identical secret keys between nodes using Cuckoo filters and a Map-Reduce model for frame hashing, ensuring long-term security in IoT environments.
Long-term evolution-advanced (LTE-A) networks exploit low-power relay nodes, picocells and femtocells to boost throughput, enhance coverage, decrease latency, and reduce cost. End users in a relay-based LTE-A network can recruit relay nodes to cooperate as virtual antenna arrays, thereby reaping the benefits offered by multiple input single output (MIMO) techniques. Although the relay-based cooperative MIMO (coop MIMO) implementation in LTE-A networks improves performance, security issues are often overlooked. This paper introduces a physical layer security scheme for point-to-point networks, and extends this scheme to MIMO networks. Two practical relay-based coop MIMO architectures and corresponding secret key generation (SKG) schemes are presented. For both the MIMO and coop MIMO networks, the impact of proposed power allocation on SKG rate (SKGR) is quantified via the theoretical and numerical analysis. Results indicate that the proposed power allocation scheme can offer 15%-30% increase in SKGR relative to MIMO/coop MIMO networks with equal power allocation at low-power region, thereby improving network security.
Due to the broadcast nature of wireless channels, wireless communication is vulnerable to eavesdropping, message modification, and node impersonation. Securing the wireless communication requires the shared secret keys between the communicating entities. Traditional security schemes rely on public key infrastructures and cryptographic algorithms to manage secret keys. Recently, many physical-layer-based methods have been proposed as alternative solutions for key generation in wireless networks. These methods exploit the inherent randomness of the wireless fading channel to generate secret keys while providing information-theoretical security without intensive cryptographic computations. This article provides an overview of the existing PHY-based key generation schemes exploiting the randomness of the wireless channels. Specifically, we first introduce the fundamental and general framework of the PHY-based key generation schemes and then categorize them into two classes: received-signal-strength-based and channel- phase-based protocols. Finally, we present a performance comparison of them in terms of key disagreement probability, key generation rate, key bit randomness, scalability, and implementation issues.
The fifth generation (5G) and beyond wireless communications will transform many exciting applications and trigger massive data connections with private, confidential, and sensitive information. The security of wireless communications is conventionally established by cryptographic schemes and protocols in which the secret key distribution is one of the essential primitives. However, traditional cryptography-based key distribution protocols might be challenged in the 5G and beyond communications because of special features such as device-to-device and heterogeneous communications, and ultra-low latency requirements. Channel reciprocity-based key generation (CRKG) is an emerging physical layer-based technique to establish secret keys between devices. This article reviews CRKG when the 5G and beyond networks employ three candidate technologies: duplex modes, massive multiple-input multiple-output (MIMO) and mmWave communications. We identify the opportunities and challenges for CRKG and provide corresponding solutions. To further demonstrate the feasibility of CRKG in practical communication systems, we overview existing prototypes with different IoT protocols and examine their performance in real-world environments. This article shows the feasibility and promising performances of CRKG with the potential to be commercialized.