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: "security and protocol exploit analysis of the 5g specifications"
  Abstract: The Third Generation Partnership Project (3GPP) released its first 5G security specifications in March 2018. This paper reviews the 5G security architecture, requirements and main processes and evaluates them in the context of known and new protocol exploits. Although the security has been enhanced when compared to previous generations to tackle known protocol exploits, our analysis identifies some potentially unrealistic system assumptions that are critical for security as well as a number protocol edge cases that could render 5G systems vulnerable to adversarial attacks. For example, null encryption and null authentication are supported and can be used in valid system configurations, and certain key security functions are still left outside of the scope of the specifications. Moreover, the prevention of pre-authentcation message exploits appears to rely on the implicit assumption of impractical carrier and roaming agreements and the management of public keys from all global operators. In parallel, existing threats such as International Mobile Subscriber Identity (IMSI) catchers are prevented only if the serving network enforces optional security features and if the UE knows the public key of the home network operator. The comparison with 4G LTE protocol exploits reveals that the 5G security specifications, as of Release 15, do not fully address the user privacy and network availability concerns, where one edge case can compromise the privacy, security and availability of 5G users and services.

Connected through hyperedge HE-1 (induced by source paper "the current state of affairs in 5g security and the main remaining security challenges"):
  with members:
    - "defeating the downgrade attack on identity privacy in 5g"
    - "formal analysis of 5g authentication"
    - "lte security protocol exploits and location tracking experimentation with low cost software radio"
    - "srslte an open source platform for lte evolution and experimentation"
    - "practical attacks against privacy and availability in 4g lte mobile communication systems"

Connected through hyperedge HE-2 (induced by source paper "csai open source cellular radio access network security analysis instrument"):
  with members:
    - "lte phy layer vulnerability analysis and testing using open source sdr tools"
    - "performance analysis of a mission critical portable lte system in targeted rf interference"
    - "lte security protocol exploits and location tracking experimentation with low cost software radio"
    - "srslte an open source platform for lte evolution and experimentation"
    - "practical attacks against privacy and availability in 4g lte mobile communication systems"

Connected through hyperedge HE-3 (induced by source paper "iot technologies for augmented human a survey"):
  with members:
    - "residual energy based cluster head selection in wsns for iot application"
    - "analysis of millimeter wave networked wearables in crowded environments"
    - "an overview of ieee 802 15 6 standard"

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)