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 "onionchain towards balancing privacy and traceability of blockchain based applications"):
  Abstract: With the popularity of Blockchain comes grave security-related concerns. Achieving privacy and traceability simultaneously remains an open question. Efforts have been made to address the issues, while they may subject to specific scenarios. This paper studies how to provide a more general solution for this open question. Concretely, we propose Onionchain, featuring a suite of protocols, offering both traceability and privacy. As the term implies, our Onionchain is inspired by Onion routing. We investigate the principles of Onion routing carefully and integrate its mechanism together with Blockchain technology. We advocate the Blockchain community to adopt Onionchain with the regards of privacy and traceability. To this end, a case-study of Onionchain, which runs in the context of Vehicular Ad Hoc Networks (VANETs), is proposed, providing the community a guideline to follow. Systematic security analysis and extensive experiments are also conducted to validate our secure and cost-effective Onionchain.

Includes members:
  Member "zebralancer private and anonymous crowdsourcing system atop open blockchain":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "a blockchain based approach for saving and tracking differential privacy cost")
  Member "an empirical analysis of linkability in the monero blockchain":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "simulated blockchains for machine learning traceability and transaction values in the monero network")
  Member "intelligent vehicle trust point reward based intelligent vehicle communication using blockchain":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "towards secure blockchain enabled internet of vehicles optimizing consensus management using reputation and contract theory")
  Member "blockchain a distributed solution to automotive security and privacy":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "assuring automotive data and software integrity employing distributed hash tables and blockchain")
  Member "blockchain based intelligent vehicle data sharing framework":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "dmap a distributed blockchain based framework for online mapping in smart city")
  Member "securing vehicle to vehicle communications using blockchain through visible light and acoustic side channels":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "blockchain for the internet of things present and future")

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)