human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "a survey on context based co presence detection techniques"):
  Abstract: In this paper, we present a systematic survey on the proximity verification techniques that are being used in Zero-Interaction based Co-presence Detection and Authentication (ZICDA) systems. First, we discuss the possible adversary and communication models, and the existing security attacks on ZICDA systems. Then, we review the state-of-the-art proximity verification techniques that make use of contextual information. Such techniques are commonly referred as Contextual Co-presence (COCO) protocols, which dynamically collect and use the specific contextual information to improve the security of such systems. Finally, we summarize the major challenges and suggest the possible innovation and efficient future solutions for securely detecting co-presence between devices. Based on our review, we observe that detecting co-presence between devices is not only challenging but also a significant contemporary research problem. The proximity verification techniques presented in the literature usually involve trade-offs between metrics such as efficiency, security, and usability. However, currently, there is no ideal solution which adequately addresses the trade-off between these metrics. Therefore, we trust that this review gives an insight into the strengths and shortcomings of the known research methodologies.

Includes members:
  Member "6thsense a context aware sensor based attack detector for smart devices":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "real time analysis of privacy un aware iot applications")
  Member "sound proof usable two factor authentication based on ambient sound":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "short range audio channels security survey of mechanisms applications and research challenges")
  Member "location cheating a security challenge to location based social network services":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "privacy and security in online social networks a survey")

Question: Please tell me which class the source paper belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.CR(Cryptography and Security)