Secret Key Agreement Protocol Research Articles

Covert Secret-Key Agreement Protocol Based on the Underwater Acoustic Channel

In order to cope with the problem of information leakage of existing secret-key agreement protocols under the environment of underwater acoustic channel (UAC), a covert secret-key agreement protocol called CSAP is proposed. In CSAP, the transmitter sends the uniformly distributed random messages to the receiver within a certain range of power constraints to ensure the reliability and the covertness of the protocol. The receiver calculates the estimated messages with Gibbs sampling according to the variance information of the underwater noise and uses the Log-Likelihood Ratio (LLR) test to extract the secret-key so as to reduce the uncertainty and the bit error rate (BER) of data transmission between two legitimate parties. The complexity of the CSAP protocol is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${O}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}$ </tex-math></inline-formula> ), where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${n}$ </tex-math></inline-formula> denotes the message length. The secrecy, covertness, and reliability of the CSAP protocol are proved by the information theory. The simulation results show that the CSAP protocol reduces the bit error rate (BER) by 28.88%, improves the secret-key generation rate by 25.70%, and decreases the communication cost by 11.32% on average compared to the existing protocol.

LORENA: Low memORy symmEtric-Key geNerAtion Method for Based on Group Cryptography Protocol Applied to the Internet of Healthcare Things

The advent of the Internet of Things (IoT) has revolutionized the way we, as a society, perform different daily tasks, such as healthcare. The Internet of Health Things (IoHT) is an example of the IoT specialization handling sensitive user data and applications requiring solutions to address different security and privacy issues. IoHT requires security mechanisms in communication. However, these mechanisms need to consider the limitations of the IoHT devices and communication. Hence, symmetric cryptography is suitable to IoHT once it uses less computational and communication resources than asymmetric cryptography. But, symmetric cryptography relies on the agreement of the cryptography material (e.g., the cryptography key) among the devices, a challenge in networks with resource constraints, such as IoHT. Therefore, this article presents a Low memORy symmEtric-key geNerAtion (LORENA) method based on group secret key agreement protocol for IoHT environments. Evaluations have focused on computational efficiency, data security requirements, and scalability in a network with up to ten devices per group using a simulator and a device with limited computational resources. Results show that the protocol is lightweight, secure, and feasible to IoHT networks, presenting a linear growth in the 128-bit key distribution time for each device entering the group.

Confidentiality and Timeliness of Data Dissemination in Platoon-based Vehicular Cyber-Physical Systems

Recent advances in inter-vehicle wireless communications allow for automated and coordinated vehicles' driving in platoon-based vehicular cyber-physical systems (PVCPS). This article presents a comprehensive low-latency cooperative security (LLCS) framework for secure and timely data dissemination in PVCPS. A new cooperative secret key agreement protocol is incorporated to produce secret keys for platooning vehicles based on their radio channel correlation. A new transmit rate adaptation mechanism is presented to minimize the end-to-end latency of the data dissemination in PVCPS. We also numerically test the confidentiality and timeliness of the LLCS framework in terms of key agreement probability and dissemination delay. It is believed that the LLCS framework is the demand of the time to enable secure and reliable autonomous driving for future PVCPS.

Security-enhanced three-party pairwise secret key agreement protocol for fog-based vehicular ad-hoc communications

The notion of fog-based vehicular ad-hoc network has been introduced by the integration of fog-based computing paradigm into the conventional vehicular ad-hoc networks. This integration is envisioned to bring a more enjoyable driving environment with an enhanced level of safety. Evidently, one of the most challenging steps in reaching this goal is how to make these immense communications secure. Shared secret key agreement protocols are one of the approved techniques for this purpose if implemented and used properly. A considerable number of such techniques proposed thus far; nevertheless, they have mostly failed to reach all required security metrics besides a desirable performance. Therefore, to address this influential demand, in this article, after the cryptanalysis of a state-of-the-art and distinguished protocol, we put forward a security-enhanced three-party pairwise shared key agreement protocol for fog-based vehicular communications with 23.65% improvement in computational cost. In addition to informal justifications, the proposed protocol is also verified formally by utilization of reputable “ProVerif” tool. In particular, comparative evaluations are presented in terms of security metrics and performance to demonstrate the appropriateness and betterment of the proposed protocol in case of simultaneous consideration of security and efficiency.

An efficient secret key agreement protocol based on random noise without beacons

ABSTRACTComputationally lightweight and unconditionally secure key agreement protocols are very useful for secure communication in public networks, especially for sensors with limited computing resources. In 2017, Guan and Tseng proposed a key agreement protocol which is computationally lightweight and unconditionally secure. In their protocol, it was assumed that the two communicating nodes can receive random bit string from a beacon node. Random bit string plays an important role in the generation of secret keys. With the advancement of hardware and software technologies, sensors may be able to generate good random strings. In this paper, we consider the case that the sensor nodes can generate random bit strings for secret keys. Therefore, no beacon nodes are required. The results of this study show that a key agreement protocol can be much more effective and efficient in the case that the communicating nodes can generate good random bit strings.

An Operational Characterization of Mutual Information in Algorithmic Information Theory

We show that the mutual information, in the sense of Kolmogorov complexity, of any pair of strings x and y is equal, up to logarithmic precision, to the length of the longest shared secret key that two parties—one having x and the complexity profile of the pair and the other one having y and the complexity profile of the pair—can establish via a probabilistic protocol with interaction on a public channel. For ℓ &gt; 2, the longest shared secret that can be established from a tuple of strings ( x 1 , …, x ℓ ) by ℓ parties—each one having one component of the tuple and the complexity profile of the tuple—is equal, up to logarithmic precision, to the complexity of the tuple minus the minimum communication necessary for distributing the tuple to all parties. We establish the communication complexity of secret key agreement protocols that produce a secret key of maximal length for protocols with public randomness. We also show that if the communication complexity drops below the established threshold, then only very short secret keys can be obtained.

Identity Management and Access Control Based on Blockchain under Edge Computing for the Industrial Internet of Things

Edge computing provides a unified platform for computing, networking, and storage resources, enabling data to be processed in a timely and efficient manner near the source. Thus, it has become the basic platform for industrial Internet of things (IIoT). However, computing′s unique features have also introduced new security problems. To solve the problem, in this paper, blockchain-based identity management combining access control mechanism is designed under edge computing. The self-certified cryptography is utilized to realize the registration and authentication of network entities. We bind the generated implicit certificate to its identity and construct the identity and certificate management mechanism based on blockchain. Secondly, an access control mechanism based on Bloom filter is designed and integrated with identity management. Moreover, for secure communication in resource-constrained edge devices, a lightweight secret key agreement protocol based on self-authenticated public key is constructed. These mechanisms work together to provide data security guarantees for IIoT such as authentication, auditability, and confidentiality.

Secret sharing-based authentication and key agreement protocol for machine-type communications

One of the main challenges for the development of the Internet of Things is the authentication of large numbers of devices/sensors, commonly served by massive machine-type communications, which joi...

Spatial Signature Modulation: A Novel Secure Modulation Approach for MIMO Wiretap Channel

Security in physical and application layers have been always thought of as a complementary paradigm. In this paper, we argue that potential cooperation between physical and application layers provides several advantages and unique features that are not available in each paradigm by itself. The problem of exchanging confidential messages between nodes, A and B, in the presenceof an active adversary, E, over an insecure MIMO channel is considered. We introduce a double layer spatial signature modulation (SSM) in which the transmitted information is conveyed into the spatial signature of the transmitting antenna array observed by the intended receiver. Meanwhile, any other eavesdropper does not share the same bearing angle of the legitimate receiver obtains infinitesimally small amount of information. Further, to establish a secure link, A and B are required to share a secret common information prior to communication while keeping E ignorant about it. To that end, we introduce a novel physical layer assisted secret key agreement (SKA) protocol that leverages the cooperation between physical and application layer security. Angle of Arrival (AoA) and Angle of Departure (AoD) are physical layer parameters that can be exploited not only for their well performance at low SNR, but also for their contextual meaning that provides security advantages. In the proposed SKA protocol, AoA is explored as a physical mean for message source authentication, meanwhile, AoD is used as a common source of randomness in a smart signal processing approach to generate secret key bits without any extra communication overhead. We show that E can be kept ignorant about the generated key bit stream conditioned on its physical location. This work introduces the notion of physical hardness to an adversary pursuing either active or passive strategy. After establishing a secret common information, we show that the continuous use of AoA as a mean for message source authenticity provides a considerable advantage against active adversary during the message exchange phase. Extending the proposed scheme to a mobile communication environment is also provided. Finally, quantitative analysis for the security gain due to the potential cooperation between physical and application layer security is developed..

Multi-Party Secret Key Agreement Over State-Dependent Wireless Broadcast Channels

We consider a group of $m$ trusted and authenticated nodes that aim to create a shared secret key $K$ over a wireless channel in the presence of an eavesdropper Eve. We assume that there exists a state-dependent wireless broadcast channel from one of the honest nodes to the rest of them including Eve. All of the trusted nodes can also discuss over a cost-free, noiseless and unlimited rate public channel which is also overheard by Eve. For this setup, we develop an information-theoretically secure secret key agreement protocol. We show the optimality of this protocol for “linear deterministic” wireless broadcast channels. This model generalizes the packet erasure model studied in the literature for wireless broadcast channels. Here, the main idea is to convert a deterministic channel into multiple independent erasure channels by using superposition coding. For “state-dependent Gaussian” wireless broadcast channels, by using insights from the deterministic problem, we propose an achievability scheme based on a multi-layer wiretap code. By using the wiretap code, we can mimic the phenomenon of converting the wireless channel into multiple independent erasure channels. Then, finding the best achievable secret key generation rate leads to solving a non-convex power allocation problem over these channels (layers). We show that using a dynamic programming algorithm, one can obtain the best power allocation for this problem. Moreover, we prove the optimality of the proposed achievability scheme for the regime of high-SNR and large-dynamic range over the channel states in the (generalized) degrees of freedom sense.

Gaussian Intrinsic Entanglement.

We introduce a cryptographically motivated quantifier of entanglement in bipartite Gaussian systems called Gaussian intrinsic entanglement (GIE). The GIE is defined as the optimized mutual information of a Gaussian distribution of outcomes of measurements on parts of a system, conditioned on the outcomes of a measurement on a purifying subsystem. We show that GIE vanishes only on separable states and exhibits monotonicity under Gaussian local trace-preserving operations and classical communication. In the two-mode case, we compute GIE for all pure states as well as for several important classes of symmetric and asymmetric mixed states. Surprisingly, in all of these cases, GIE is equal to Gaussian Rényi-2 entanglement. As GIE is operationally associated with the secret-key agreement protocol and can be computed for several important classes of states, it offers a compromise between computable and physically meaningful entanglement quantifiers.

Secret Key Agreement: General Capacity and Second-Order Asymptotics

We revisit the problem of secret key agreement using interactive public communication for two parties and propose a new secret key agreement protocol. The protocol attains the secret key capacity for general observations and attains the second-order asymptotic term in the maximum length of a secret key for independent and identically distributed observations. In contrast to the previously suggested secret key agreement protocols, the proposed protocol uses interactive communication. In fact, the standard one-way communication protocol used prior to this paper fails to attain the asymptotic results above. Our converse proofs rely on a recently established upper bound for secret key lengths. Both our lower and upper bounds are derived in a single-shot setup and the asymptotic results are obtained as corollaries.

Secret Key Agreement With Large Antenna Arrays Under the Pilot Contamination Attack

We present a secret key agreement (SKA) protocol for a multi-user time-division duplex system where a base-station (BS) with a large antenna array (LAA) shares secret keys with users in the presence of non-colluding eavesdroppers. In the system, when the BS transmits random sequences to legitimate users for sharing common randomness, the eavesdroppers can attempt the pilot contamination attack (PCA) in which each of eavesdroppers transmits its target user's training sequence in hopes of acquiring possible information leak by steering beam towards the eavesdropper. We show that there exists a crucial complementary relation between the received signal strengths at the eavesdropper and its target user. This relation tells us that the eavesdropper inevitably leaves a trace that enables us to devise a way of measuring the amount of information leakage to the eavesdropper even if PCA parameters are unknown. To this end, we derive an estimator for the channel gain from the BS to the eavesdropper and propose a rate-adaptation scheme for adjusting the length of secret key under the PCA. Extensive analysis and evaluations are carried out under various setups, which show that the proposed scheme adequately takes advantage of the LAA to establish the secret keys under the PCA.

Cooperative Key Agreement for Wireless Networking: Key Rates and Practical Protocol Design

In this paper, we investigate the design of a practical information-theoretically secure secret key agreement protocol for a cooperative wireless network employing standard modulation. Assuming relay selection has been completed, the key agreement problem is studied in a three-node cooperative wireless communication system over block-fading channels. Passive attacks from an eavesdropper collocated with the relay are considered. We derive upper and lower bounds on the secret key rate of this cooperative wireless system. The difference between the bounds is shown to be small for practical communication scenarios, which indicates they are tight. We then propose a practical secret key agreement protocol for this system with both the communicants and the honest relay participating in the public discussion. The tradeoff between security and protocol efficiency is considered in the joint design of advantage distillation, information reconciliation, and privacy amplification. The protocol parameters are optimized to achieve the tight bound on the secret key rate.

Relating quantum privacy and quantum coherence: an operational approach.

Given many realizations of a state or a channel as a resource, two parties can generate a secret key as well as entanglement. We describe protocols to perform the secret key distillation (as it turns out, with optimal rate). Then we show how to achieve optimal entanglement generation rates by "coherent" implementation of a class of secret key agreement protocols, proving the long-conjectured "hashing inequality."

The effect of side-information on smooth entropy

This paper gives the effect of side-information, obtained by the opponent through an initial reconciliation step, on the size of the secret-key that can be distilled safely by subsequent privacy amplification in unconditionally secure secret-key agreement protocol based on smooth entropy, and obtains the size of the secret-key.

Creating Strong, Total, Commutative, Associative One-Way Functions from Any One-Way Function in Complexity Theory

Rabi and Sherman presented novel digital signature and unauthenticated secret-key agreement protocols, developed by themselves and by Rivest and Sherman. These protocols use strong, total, commutative (in the case of multiparty secret-key agreement), associative one-way functions as their key building blocks. Although Rabi and Sherman did prove that associative one-way functions exist if P≠NP, they left as an open question whether any natural complexity-theoretic assumption is sufficient to ensure the existence of strong, total, commutative, associative one-way functions. In this paper, we prove that if P≠NP then strong, total, commutative, associative one-way functions exist.

Generalized privacy amplification

This paper, provides a general treatment of privacy amplification by public discussion, a concept introduced by Bennett, Brassard, and Robert for a special scenario. Privacy amplification is a process that allows two parties to distil a secret key from a common random variable about which an eavesdropper has partial information. The two parties generally know nothing about the eavesdropper's information except that it satisfies a certain constraint. The results have applications to unconditionally secure secret-key agreement protocols and quantum cryptography, and they yield results on wiretap and broadcast channels for a considerably strengthened definition of secrecy capacity.