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: "torbricks blocking resistant tor bridge distribution"
  Abstract: Tor is currently the most popular network for anonymous Internet access. It critically relies on volunteer nodes called bridges for relaying Internet traffic when a user's ISP blocks connections to Tor. Unfortunately, current methods for distributing bridges are vulnerable to malicious users who obtain and block bridge addresses. In this paper, we propose TorBricks, a protocol for distributing Tor bridges to n users, even when an unknown number t < n of these users are controlled by a malicious adversary. TorBricks distributes O(tlog(n)) bridges and guarantees that all honest users can connect to Tor with high probability after O(log(t)) rounds of communication with the distributor. #R##N#We also extend our algorithm to perform privacy-preserving bridge distribution when run among multiple untrusted distributors. This not only prevents the distributors from learning bridge addresses and bridge assignment information, but also provides resistance against malicious attacks from a m/3 fraction of the distributors, where m is the number of distributors.

Connected through hyperedge HE-1 (induced by source paper "resource competitive sybil defenses"):
  with members:
    - "proof of work without all the work"
    - "secure one way interactive communication"
    - "interactive communication with unknown noise rate"
    - "bitcoin ng a scalable blockchain protocol"
    - "the mason test a defense against sybil attacks in wireless networks without trusted authorities"
    - "self healing computation"
    - "the sybil attacks and defenses a survey"
    - "quorums quicken queries efficient asynchronous secure multiparty computation"

Connected through hyperedge HE-2 (induced by source paper "scalable and secure computation among strangers resource competitive byzantine protocols"):
  with members:
    - "time message trade offs in distributed algorithms"
    - "sending a message with unknown noise"
    - "interactive communication with unknown noise rate"
    - "bitcoin ng a scalable blockchain protocol"
    - "sublinear bounds for randomized leader election"
    - "making evildoers pay resource competitive broadcast in sensor networks"
    - "breaking the o n 2 bit barrier scalable byzantine agreement with an adaptive adversary"

Connected through hyperedge HE-3 (induced by source paper "an empirical study of the i2p anonymity network and its censorship resistance"):
  with members:
    - "censors delay in blocking circumvention proxies"
    - "raptor routing attacks on privacy in tor"
    - "content and popularity analysis of tor hidden services"

Connected through hyperedge HE-4 (induced by source paper "proof of work without all the work computationally efficient attack resistant systems"):
  with members:
    - "proof of work without all the work"
    - "secure one way interactive communication"
    - "interactive communication with unknown noise rate"
    - "the mason test a defense against sybil attacks in wireless networks without trusted authorities"
    - "self healing computation"
    - "the sybil attacks and defenses a survey"
    - "storage and search in dynamic peer to peer networks"
    - "making evildoers pay resource competitive broadcast in sensor networks"

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)