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 "chainspace a sharded smart contracts platform"):
  Abstract: Chainspace is a decentralized infrastructure, known as a distributed ledger, that supports user defined smart contracts and executes user-supplied transactions on their objects. The correct execution of smart contract transactions is verifiable by all. The system is scalable, by sharding state and the execution of transactions, and using S-BAC, a distributed commit protocol, to guarantee consistency. Chainspace is secure against subsets of nodes trying to compromise its integrity or availability properties through Byzantine Fault Tolerance (BFT), and extremely high-auditability, non-repudiation and `blockchain' techniques. Even when BFT fails, auditing mechanisms are in place to trace malicious participants. We present the design, rationale, and details of Chainspace; we argue through evaluating an implementation of the system about its scaling and other features; we illustrate a number of privacy-friendly smart contracts for smart metering, polling and banking and measure their performance.

Includes members:
  Member "enhancing bitcoin security and performance with strong consistency via collective signing":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "surface a practical blockchain consensus algorithm for real world networks")
  Member "xft practical fault tolerance beyond crashes":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "two more algorithms for randomized signature free asynchronous binary byzantine consensus with t n 3 and o n 2 messages and o 1 round expected termination")
  Member "centrally banked cryptocurrencies":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "on the feasibility of sybil attacks in shard based permissionless blockchains")
  Member "bitcoin meets strong consistency":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "on the feasibility of sybil attacks in shard based permissionless blockchains")
  Member "plug in privacy for smart metering billing":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "the influence of differential privacy on short term electric load forecasting")
  Member "consensus on transaction commit":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "blockchain meets database design and implementation of a blockchain relational database")

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)