human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "a secure consensus protocol for sidechains"):
  Abstract: Sidechain technology has been envisioned as a promising solution to accelerate today's public blockchains in terms of scalability and interoperability. By relying on the mainchain for security, different sidechains can formulate their own rules to reach consensus. Although the literature has considered the possibility of using consensus protocols in the sidechain, so far a tailor-made consensus protocol for sidechains with high performance and formal security proof has not been attempted. To fill this gap, we introduce Cumulus, a low overhead, highly efficient, security provable sidechain protocol. Cumulus makes use of smart contracts to ensure that only one block proposed in the sidechain will be enforced on the mainchain in each round, thereby achieving consensus in an efficient manner. We give a formal specification of Cumulus which ensures safety and liveness without any online requirements of clients. For security analysis, we provide formal security definitions and proofs under Universally Composable Security (UCS) model. As a proof of concept, we implement Cumulus and evaluate it in an Ethereum testnet.

Includes members:
  Member "selfish mining in ethereum":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "a survey on ethereum systems security vulnerabilities attacks and defenses")
  Member "flash efficient dynamic routing for offchain networks":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "toward active and passive confidentiality attacks on cryptocurrency off chain networks")
  Member "proteus a scalable bft consesus protocol for blockchains":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "flow separating consensus and compute")
  Member "sbft a scalable and decentralized trust infrastructure":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "expected linear round synchronization the missing link for linear byzantine smr")
  Member "hotstuff bft consensus in the lens of blockchain":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "surface a practical blockchain consensus algorithm for real world networks")
  Member "routing cryptocurrency with the spider network":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "hushrelay a privacy preserving efficient and scalable routing algorithm for off chain payments")
  Member "a scale out blockchain for value transfer with spontaneous sharding":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "effective scaling of blockchain beyond consensus innovations and moore s law")
  Member "window based bft blockchain consensus":
    also connected through other hyperedges:
      - Hyperedge HE-8 (induced by source paper "proteus a scalable bft consesus protocol for blockchains")

Question: Please tell me which class the source paper 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)