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: "a survey of hardware based control flow integrity cfi"
  Abstract: CFI is a computer security technique that detects runtime attacks by monitoring a program's branching behavior. This work presents a detailed analysis of the security policies enforced by 21 recent hardware-based CFI architectures. The goal is to evaluate the security, limitations, hardware cost, performance, and practicality of using these policies. We show that many architectures are not suitable for widespread adoption, since they have practical issues, such as relying on accurate control flow model (which is difficult to obtain) or they implement policies which provide only limited security.

Connected through hyperedge HE-1 (induced by source paper "sok hardware security support for trustworthy execution"):
  with members:
    - "secloak arm trustzone based mobile peripheral control"
    - "reverse engineering x86 processor microcode"
    - "extracting secrets from encrypted virtual machines"
    - "sgxpectre stealing intel secrets from sgx enclaves via speculative execution"
    - "spectre attacks exploiting speculative execution"
    - "pac it up towards pointer integrity using arm pointer authentication"
    - "lord of the x86 rings a portable user mode privilege separation architecture on x86"
    - "severed subverting amd s virtual machine encryption"

Connected through hyperedge HE-2 (induced by source paper "a survey of cyber security countermeasures using hardware performance counters"):
  with members:
    - "cacheshield protecting legacy processes against cache attacks"
    - "sigdrop signature based rop detection using hardware performance counters"
    - "anomaly detection for malware identification using hardware performance counters"

Connected through hyperedge HE-3 (induced by source paper "a multilevel cybersecurity and safety monitor for embedded cyber physical systems"):
  with members:
    - "a model based approach to security analysis for cyber physical systems"

Connected through hyperedge HE-4 (induced by source paper "sponge based control flow protection for iot devices"):
  with members:
    - "rowhammer js a remote software induced fault attack in javascript"

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)