Key Technologies Of Security-aware Device-to-Device Communications

Device-to-Device(D2D)communications,which allow two nearby devices to communicate directly with each other,are introduced in the fifth generation mobile communication systems(5G)to offload the overburden networks.It becomes a key technology in 5G.However,with the rapid development of mobile communication technology,the mobile services range from voice,data,e-commerce to mobile payment,which generate large amounts of privacy-sensive data in the wireless channels.Consequently,security issues arise with the development of mobile services.It is challenging and important to protect the security of the data and user's privacy in D2D communicaitons.Unfortunately,there are limited researches on security issues in D2D communications.The existing works mainly focus on attack detection or privacy preservation while ignoring the data security.In this work,secure data transmission schemes are proposed to resist attacks such as eavesdropping and modifying based on cryptography techniques.The main contributions are as follows:(1)Considering the security of the cryptography technique is determined by the secrecy of the keys,a Robust Secure Key Agreement(RSKA)scheme from Received Signal Strength(RSS)of D2D channel is proposed.In order to mitigate the asymmetry in RSS measurements for communicating parties,the sender and receiver normalize RSS measurements and quantize them into q-bit sequences.They then reshape bit sequences into new/-bit sequences.These bit sequences work as key sources.Rather than extracting the key from the key sources directly,the sender randomly generates a bit sequence as a key and hides it in a promise.This is created from a polynomial constructed on the sender's key source and key.The receiver recovers the key by reconstructing a polynomial from its key source and the promise.The analysis shows that the shared key generated by our proposed RSKA scheme has features of high randomness and a high bit rate compared to traditional RSS-based key agreement schemes.(2)A secure data sharing protocol,which merges the advantages of public key cryptography and symmetric encryption,is proposed to achieve data security in D2D communications.Specifically,a public-key-based digital signature,combined with mutual authentication mechanism of cellular network,guarantees entity authentication,transmission nonrepudiation,traceability,data authority,and integrity.Meanwhile,symmetric encryption is employed to ensure data confiden-tiality.A salient feature of the proposed protocol is that it can detect free-riding attack by keeping a record of the current status for user equipment(UE)and realize reception nonrepudiation by key hint transmission between the UE and evolved NodeB(eNB),thus improving system availability.Furthermore,various delay models are established in different application scenarios to seek the optimal initial service providers(SPs)for achieving tradeoff between cost and availability.Extensive analysis and simulations demonstrate that the proposed protocol is indeed an efficient and practical solution for a secure data sharing mechanism for D2D communications.(3)A Light-weight and Robust Security-Aware(LRSA)D2D-assist data transmission protocol for mobile health systems is proposed by using certificateless generalized signcryption technique.Specifically,a new efficient CertificateLess Generalized SignCryption(CLGSC)scheme is prpoposed.It can adaptively work as one of the three cryptographic primitives:signcryption,signature,or encryption,but within one single algorithm.The scheme is proven to be secure,simultaneously achieving confidentiality and unforgeability.Based on the proposed CLGSC algorithm,we further design a D2D-assist data transmission protocol for mobile health systems with security properties including data confidentiality and integrity,mutual authentication,contextual privacy,anonymity,unlinkability,and forward security.Performance analysis demonstrates that the proposed protocol can achieve the design objectives and outperform existing schemes in terms of computational and communication overhead.(4)The inherent characteristics of wireless channels are explored to prevent eavesdropping.Firstly,a power control scheme is designed to obtain the optimal transmission powers for the D2D links without violating secrecy requirement of cellular users.Then,the problem is formulated as a stochastic optimization problem,aiming at maximizing the secrecy capacity gain of D2D communications.By solving the expected value model for the stochastic optimization problem,the optimal D2D links are selected to realize maximal ergodic secrecy capacity gain.Specifically,a weighted conflict graph is formulated according to the protocol model.Thus,the optimization problem has been transformed to the maximum weighted independent set problem,which is solved by a greedy weighted minimum degree algorithm.Simulation results demonstrate that the content dissemination scheme with power control can bring high secrecy capacity gain to the network.