human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "password protected smart card and memory stick authentication against off line dictionary attacks"
  Abstract: In this paper, we study the security requirements for remote authentication with password protected smart card. In recent years, several protocols for password-based authenticated key exchange have been proposed. These protocols are used for the protection of password based authentication between a client and a remote server. In this paper, we will focus on the password based authentication between a smart card owner and smart card via an untrusted card reader. In a typical scenario, a smart card owner inserts the smart card into an untrusted card reader and input the password via the card reader in order for the smart card to carry out the process of authentication with a remote server. In this case, we want to guarantee that the card reader will not be able to impersonate the card owner in future without the smart card itself. Furthermore, the smart card could be stolen. If this happens, we want the assurance that an adversary could not use the smart card to impersonate the card owner even though the sample space of passwords may be small enough to be enumerated by an off-line adversary. At the end of this paper, we further extend our results to credential storage on portable non-tamper resistant storage devices such as USB memory sticks.

Connected through hyperedge HE-1 (induced by source paper "authentication protocols for internet of things a comprehensive survey"):
  with members:
    - "a survey on privacy preserving schemes for smart grid communications"
    - "data collection and wireless communication in internet of things iot using economic analysis and pricing models a survey"
    - "privacy in the internet of things threats and challenges"
    - "the emerging internet of things marketplace from an industrial perspective a survey"
    - "a survey on internet of things from industrial market perspective"
    - "context aware computing for the internet of things a survey"
    - "internet of things iot a vision architectural elements and future directions"
    - "public key cryptography standards pkcs"

Connected through hyperedge HE-2 (induced by source paper "a survey on privacy preserving schemes for smart grid communications"):
  with members:
    - "technical privacy metrics a systematic survey"
    - "privacy discovery and authentication for the internet of things"
    - "combining ensemble methods and social network metrics for improving accuracy of ocsvm on intrusion detection in scada systems"
    - "the mason test a defense against sybil attacks in wireless networks without trusted authorities"

Question: Please tell me which class the center node 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)