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: "strong federations an interoperable blockchain solution to centralized third party risks"
  Abstract: Bitcoin, the first peer-to-peer electronic cash system, opened the door to permissionless, private, and trustless transactions. Attempts to repurpose Bitcoin's underlying blockchain technology have run up against fundamental limitations to privacy, faithful execution, and transaction finality. We introduce \emph{Strong Federations}: publicly verifiable, Byzantine-robust transaction networks that facilitate movement of any asset between disparate markets, without requiring third-party trust. \emph{Strong Federations} enable commercial privacy, with support for transactions where asset types and amounts are opaque, while remaining publicly verifiable. As in Bitcoin, execution fidelity is cryptographically enforced; however, \emph{Strong Federations} significantly lower capital requirements for market participants by reducing transaction latency and improving interoperability. To show how this innovative solution can be applied today, we describe \emph{\liquid}: the first implementation of \emph{Strong Federations} deployed in a Financial Market.

Connected through hyperedge HE-1 (induced by source paper "snappy fast on chain payments with practical collaterals"):
  with members:
    - "dfinity technology overview series consensus system"
    - "gosig scalable byzantine consensus on adversarial wide area network for blockchains"
    - "towards an economic analysis of routing in payment channel networks"
    - "sprites and state channels payment networks that go faster than lightning"
    - "consensus in the age of blockchains"
    - "casper the friendly finality gadget"

Connected through hyperedge HE-2 (induced by source paper "zendoo a zk snark verifiable cross chain transfer protocol enabling decoupled and decentralized sidechains"):
  with members:
    - "sidechains decoupled consensus between chains"

Connected through hyperedge HE-3 (induced by source paper "towards global asset management in blockchain systems"):
  with members:
    - "atomic commitment across blockchains"
    - "parblockchain leveraging transaction parallelism in permissioned blockchain systems"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "atomic cross chain swaps"
    - "sidechains decoupled consensus between chains"
    - "blockchains consensus protocols in the wild"
    - "sprites and state channels payment networks that go faster than lightning"
    - "adding concurrency to smart contracts"

Connected through hyperedge HE-4 (induced by source paper "blockchain inspired event recording system for autonomous vehicles"):
  with members:
    - "blackchain scalability for resource constrained accountable vehicle to x communication"
    - "securing vehicle to vehicle communications using blockchain through visible light and acoustic side channels"
    - "the miner s dilemma"

Connected through hyperedge HE-5 (induced by source paper "sprites and state channels payment networks that go faster than lightning"):
  with members:
    - "concurrency and privacy with payment channel networks"
    - "instantaneous decentralized poker"
    - "enhancing bitcoin security and performance with strong consistency via collective signing"
    - "bitcoin ng a scalable blockchain protocol"

Connected through hyperedge HE-6 (induced by source paper "ontology of blockchain technologies principles of identification and classification"):
  with members:
    - "a perspective on blockchain smart contracts reducing uncertainty and complexity in value exchange"
    - "a survey on security and privacy issues of bitcoin"
    - "smart contract templates essential requirements and design options"

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)