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: "the loopix anonymity system"
  Abstract: We present Loopix, a low-latency anonymous communication system that provides bi-directional 'third-party' sender and receiver anonymity and unobservability. Loopix leverages cover traffic and brief message delays to provide anonymity and achieve traffic analysis resistance, including against a global network adversary. Mixes and clients self-monitor the network via loops of traffic to provide protection against active attacks, and inject cover traffic to provide stronger anonymity and a measure of sender and receiver unobservability. Service providers mediate access in and out of a stratified network of Poisson mix nodes to facilitate accounting and off-line message reception, as well as to keep the number of links in the system low, and to concentrate cover traffic. We provide a theoretical analysis of the Poisson mixing strategy as well as an empirical evaluation of the anonymity provided by the protocol and a functional implementation that we analyze in terms of scalability by running it on AWS EC2. We show that a Loopix relay can handle upwards of 300 messages per second, at a small delay overhead of less than 1.5 ms on top of the delays introduced into messages to provide security. Overall message latency is in the order of seconds - which is low for a mix-system. Furthermore, many mix nodes can be securely added to a stratified topology to scale throughput without sacrificing anonymity.

Connected through hyperedge HE-1 (induced by source paper "prifi low latency anonymity for organizational networks"):
  with members:
    - "taranet traffic analysis resistant anonymity at the network layer"
    - "i know what you saw last minute encrypted http adaptive video streaming title classification"
    - "atom horizontally scaling strong anonymity"
    - "device fingerprinting in wireless networks challenges and opportunities"
    - "riposte an anonymous messaging system handling millions of users"
    - "hornet high speed onion routing at the network layer"
    - "dovetail stronger anonymity in next generation internet routing"
    - "hang with your buddies to resist intersection attacks"

Connected through hyperedge HE-2 (induced by source paper "talek private group messaging with hidden access patterns"):
  with members:
    - "xrd scalable messaging system with cryptographic privacy"
    - "atom horizontally scaling strong anonymity"
    - "riposte an anonymous messaging system handling millions of users"
    - "rappor randomized aggregatable privacy preserving ordinal response"
    - "proactively accountable anonymous messaging in verdict"

Connected through hyperedge HE-3 (induced by source paper "express lowering the cost of metadata hiding communication with cryptographic privacy"):
  with members:
    - "xrd scalable messaging system with cryptographic privacy"
    - "prio private robust and scalable computation of aggregate statistics"
    - "atom horizontally scaling strong anonymity"
    - "riposte an anonymous messaging system handling millions of users"
    - "conscript your friends into larger anonymity sets with javascript"
    - "proactively accountable anonymous messaging in verdict"

Connected through hyperedge HE-4 (induced by source paper "xrd scalable messaging system with cryptographic privacy"):
  with members:
    - "atom horizontally scaling strong anonymity"
    - "riposte an anonymous messaging system handling millions of users"

Connected through hyperedge HE-5 (induced by source paper "extending the anonymity of zcash"):
  with members:
    - "bitcoin over tor isn t a good idea"

Connected through hyperedge HE-6 (induced by source paper "taranet traffic analysis resistant anonymity at the network layer"):
  with members:
    - "raptor routing attacks on privacy in tor"
    - "hornet high speed onion routing at the network layer"
    - "dovetail stronger anonymity in next generation internet routing"
    - "hang with your buddies to resist intersection attacks"
    - "stealthy traffic analysis of low latency anonymous communication using throughput fingerprinting"

Connected through hyperedge HE-7 (induced by source paper "prifi low latency metadata protection for organizational network"):
  with members:
    - "taranet traffic analysis resistant anonymity at the network layer"
    - "riposte an anonymous messaging system handling millions of users"
    - "dovetail stronger anonymity in next generation internet routing"
    - "proactively accountable anonymous messaging in verdict"

Connected through hyperedge HE-8 (induced by source paper "atom horizontally scaling strong anonymity"):
  with members:
    - "riposte an anonymous messaging system handling millions of users"
    - "secure anonymous broadcast"
    - "hang with your buddies to resist intersection attacks"

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)