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: "towards deploying a scalable robust vehicular identity and credential management infrastructure"
  Abstract: Several years of academic and industrial research efforts have converged to a common understanding on fundamental security building blocks for the upcoming Vehicular Communication (VC) systems. There is a growing consensus towards deploying a Vehicular Public-Key Infrastructure (VPKI) enables pseudonymous authentication, with standardization efforts in that direction. However, there are still significant technical issues that remain unresolved. Existing proposals for instantiating the VPKI either need additional detailed specifications or enhanced security and privacy features. Equally important, there is limited experimental work that establishes the VPKI efficiency and scalability. In this paper, we are concerned with exactly these issues. We leverage the common VPKI approach and contribute an enhanced system with precisely defined, novel features that improve its resilience and the user privacy protection. In particular, we depart from the common assumption that the VPKI entities are fully trusted and we improve user privacy in the face of an honest-but-curious security infrastructure. Moreover, we fully implement our VPKI, in a standard-compliant manner, and we perform an extensive evaluation. Along with stronger protection and richer functionality, our system achieves very significant performance improvement over prior systems — contributing the most advanced VPKI towards deployment.

Connected through hyperedge HE-1 (induced by source paper "resilient collaborative privacy for location based services"):
  with members:
    - "impact of vehicular communications security on transportation safety"

Connected through hyperedge HE-2 (induced by source paper "scaling pseudonymous authentication for large mobile systems"):
  with members:
    - "efficient scalable and resilient vehicle centric certificate revocation list distribution in vanets"
    - "blockpki an automated resilient and transparent public key infrastructure"
    - "a security credential management system for v2x communications"
    - "vpkiaas a highly available and dynamically scalable vehicular public key infrastructure"
    - "rhythm a randomized hybrid scheme to hide in the mobile crowd"
    - "secmace scalable and robust identity and credential management infrastructure in vehicular communication systems"
    - "security and privacy in vehicular social networks"
    - "evaluating on demand pseudonym acquisition policies in vehicular communication systems"

Connected through hyperedge HE-3 (induced by source paper "resilient privacy protection for location based services through decentralization"):
  with members:
    - "resilient collaborative privacy for location based services"
    - "efficient scalable and resilient vehicle centric certificate revocation list distribution in vanets"
    - "secmace scalable and robust identity and credential management infrastructure in vehicular communication systems"
    - "geo indistinguishability differential privacy for location based systems"
    - "vespa vehicular security and privacy preserving architecture"
    - "secure vehicular communication systems design and architecture"

Connected through hyperedge HE-4 (induced by source paper "dos resilient cooperative beacon verification for vehicular communication systems"):
  with members:
    - "efficient scalable and resilient vehicle centric certificate revocation list distribution in vanets"
    - "secmace scalable and robust identity and credential management infrastructure in vehicular communication systems"
    - "scaling vanet security through cooperative message verification"

Connected through hyperedge HE-5 (induced by source paper "efficient scalable and resilient vehicle centric certificate revocation list distribution in vanets"):
  with members:
    - "a security credential management system for v2x communications"
    - "rhythm a randomized hybrid scheme to hide in the mobile crowd"
    - "secmace scalable and robust identity and credential management infrastructure in vehicular communication systems"
    - "optimized certificate revocation list distribution for secure v2x communications"
    - "evaluating on demand pseudonym acquisition policies in vehicular communication systems"
    - "the key to intelligent transportation identity and credential management in vehicular communication systems"
    - "on the road reflections on the security of vehicular communication systems"
    - "secure vehicular communication systems design and architecture"

Connected through hyperedge HE-6 (induced by source paper "vpkiaas a highly available and dynamically scalable vehicular public key infrastructure"):
  with members:
    - "a security credential management system for v2x communications"
    - "rhythm a randomized hybrid scheme to hide in the mobile crowd"
    - "secmace scalable and robust identity and credential management infrastructure in vehicular communication systems"
    - "evaluating on demand pseudonym acquisition policies in vehicular communication systems"
    - "the key to intelligent transportation identity and credential management in vehicular communication systems"

Connected through hyperedge HE-7 (induced by source paper "secmace scalable and robust identity and credential management infrastructure in vehicular communication systems"):
  with members:
    - "resilient privacy protection for location based services through decentralization"
    - "security and privacy in vehicular social networks"
    - "evaluating on demand pseudonym acquisition policies in vehicular communication systems"
    - "the key to intelligent transportation identity and credential management in vehicular communication systems"
    - "vespa vehicular security and privacy preserving architecture"
    - "on the road reflections on the security of vehicular communication systems"
    - "secure vehicular communication systems implementation performance and research challenges"
    - "impact of vehicular communications security on transportation safety"

Connected through hyperedge HE-8 (induced by source paper "security and privacy in vehicular social networks"):
  with members:
    - "resilient collaborative privacy for location based services"
    - "the key to intelligent transportation identity and credential management in vehicular communication systems"
    - "vespa vehicular security and privacy preserving architecture"
    - "secure vehicular communication systems design and architecture"

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)