The advent of industry 4.0 with its idea of individualized mass production will significantly increase the demand for more flexibility on the production floor. Wireless communication provides this type of flexibility but puts the automation system at risk as potential attackers now can eavesdrop or even manipulate the messages exchanged even without getting access to the premises of the victim. Cryptographic means can prevent, such attacks if applied properly. One of their core components is the distribution of keys. The generation of keys from channel parameters seems to be a promising approach in comparison with classical approaches based on public key cryptography as it avoids computing intense operations for exchanging keys. In this paper, we investigated key generation approaches using channel parameters recorded in a real industrial environment. Our key results are that the key generation may take unpredictable long and that the resulting keys are of low quality with respect to the test for randomness we applied.
The advent of industry 4.0 with its idea of individualized mass production will significantly increase the demand for more flexibility on the production floor. Wireless communication provides this type of flexibility but puts the automation system at risk as potential attackers now can eavesdrop or even manipulate the messages exchanged even without getting access to the premises of the victim. Cryptographic means can prevent, such attacks if applied properly. One of their core components is the distribution of keys. The generation of keys from channel parameters seems to be a promising approach in comparison with classical approaches based on public key cryptography as it avoids computing intense operations for exchanging keys. In this paper, we investigated key generation approaches using channel parameters recorded in a real industrial environment. Our key results are that the key generation may take unpredictable long and that the resulting keys are of low quality with respect to the test for randomness we applied.
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.
Key generation from the randomness of wireless channels is a promising alternative to public key cryptography for the establishment of cryptographic keys between any two users. This paper reviews the current techniques for wireless key generation. The principles, performance metrics and key generation procedure are comprehensively surveyed. Methods for optimizing the performance of key generation are also discussed. Key generation applications in various environments are then introduced along with the challenges of applying the approach in each scenario. The paper concludes with some suggestions for future studies.
Physical-layer secret key generation has emerged as a promising solution for establishing cryptographic keys by leveraging reciprocal and time-varying wireless channels. However, existing approaches suffer from low key generation rates and vulnerabilities under various attacks in slowly varying environments. We propose a new physical-layer secret key generation approach with channel obfuscation, which improves the dynamic property of channel parameters based on random filtering and random antenna scheduling. Our approach makes one party obfuscate the channel to allow the legitimate party to obtain similar dynamic channel parameters, yet prevents a third party from inferring the obfuscation information. Our approach allows more random bits to be extracted from the obfuscated channel parameters by a joint design of the K-L transform and adaptive quantization. Results from a testbed implementation show that our approach, compared to the existing ones that we evaluate, performs the best in generating high entropy bits at a fast rate and is able to resist various attacks in slowly varying environments. Specifically, our approach can achieve a significantly faster secret bit generation rate at roughly 67 bit/pkt, and the key sequences can pass the randomness tests of the NIST test suite.
The billions of IoT devices in our home, healthcare, and industry rely on cryptographic keys for security. Constrained by computing and power resources, their keys are often pre-shared and rarely updated, creating a major vulnerability. The physical-layer wireless key generation can efficiently update keys but requires fluctuating wireless channel conditions, which, however, are scarce in static deployments. Here we show a novel wireless key generation that produces secure keys for static IoT without hardware assistance or secret exchange. We propose a randomness that is composed of received signal strengths and locally selected transmit power levels; the latter are independently selected at both communication pairs and are never exchanged, resulting in distinctive received signal strengths to ensure secrecy. We propose quantization and entropy balancing to boost generation efficiency and consistency. Experiments on an IoT testbed across multiple static scenarios achieve a fast key generation rate of 9.47 bits per second and a low key disagreement rate of 0.05, while defending against eavesdropping attacks. Xintao Huan and colleagues report a physical-layer wireless key generation scheme for static IoT scenarios. This scheme does not require hardware assistance or secret exchange and achieves fast key generation in static IoT while defending against eavesdropping attacks.
Methods to generate private keys based on wireless channel characteristics have been proposed as an alternative to standard key-management schemes.In this paper, we discuss past work in the field and offer a generalized scheme for the generation of private keys using uncorrelated channels in multiple domains.Proposed cognitive enhancements measure channel coherence, to dynamically change transmission and reception parameters as well as estimate private key strength and expiration time.We evaluate a proof-of-concept implementation of this system in software using a channel model that provides variation in multiple domains. I. INTRODUCTIONFor a wireless communications link to be secure, it must provide data confidentiality and integrity during transmission.The principal method through which this is achieved is the use of cryptography, of which there are generally two types, public key [1] and private key [2].Public-key cryptography is a method for secret communication between two parties without the requirement of an initial exchange of secret keys.It employs a pair of keys, one private, which is held secret, and one public, which is distributed.Messages are encrypted with the recipient's public key and decrypted with the recipient's corresponding private key.Public-key cryptography is thus relatively unencumbered with key-exchange difficulties and key-interception vulnerabilities, however it is computationally intensive.Private-key cryptography is a method for secret communication between two parties that requires an initial exchange of a single shared secret key.Messages are encrypted by the sender and decrypted by the recipient using this same shared key.Private-key cryptography is less computationally intensive than public-key cryptography, however key distribution and management are problematic.Key distribution risks that the secret key will be intercepted during transmission.Key management requires the generation and transport of a different key for each communicating party [3].
In recent years, physical layer security has become one of the core technologies for wireless communication system security. Physical layer encryption is based on the inherent reciprocity, time-varying, spatial uniqueness and unpredictability of wireless communication systems to generate keys, which are naturally unforgeable and steganography-proof. However, the research of physical layer key generation technology also faces many challenges, such as the problem of poor key generation performance due to signal interference, the problem of lower randomness and slower key generation rate in quasi-static channel environment, and the problem of lower key consistency between two legitimate communication parties due to the existence of channel estimation errors; this paper provides a systematic explanation of the traditional model of key generation for wireless channels and a typical solution for this series of problems. In this paper, the traditional model of wireless channel key generation is systematically explained, and the typical solutions to this series of problems are studied, analysed and compared in terms of performance.