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: "equibit a peer to peer electronic equity system"
  Abstract: The registration, transfer, clearing and settlement of equities represents a significant part of economic activity currently underserved by modern technological innovation. In addition, recent events have revealed problems of transparency, inviting public criticism and scrutiny from regulatory authorities. A peer-to-peer platform facilitating the creation and exchange of directly registered shares represents a shift in equity markets towards more efficient, transparent operations as well as greater accessibility to the investing public and issuing companies. Blockchain technology solves the problem of transaction processing and clearing but the fungibility of their units pose a challenge in identifying the issuers and holders of specific equities. Furthermore, as the issuers are in a constant state of flux the benefits of a decentralized network are lost if a central manager is required to cancel equities from companies that no longer exist. We propose a solution to these problems using digital signatures, based on blockchain technology.

Connected through hyperedge HE-1 (induced by source paper "on the feasibility of decentralized derivatives markets"):
  with members:
    - "decentralized prediction market without arbiters"
    - "ipfs content addressed versioned p2p file system"

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)