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: "blockchain technology overview"
  Abstract: Blockchains are tamper evident and tamper resistant digital ledgers implemented in a distributed fashion (i.e., without a central repository) and usually without a central authority (i.e., a bank, company, or government). At their basic level, they enable a community of users to record transactions in a shared ledger within that community, such that under normal operation of the blockchain network no transaction can be changed once published. This document provides a high-level technical overview of blockchain technology. The purpose is to help readers understand how blockchain technology works.

Connected through hyperedge HE-1 (induced by source paper "dlbc a deep learning based consensus in blockchains for deep learning services"):
  with members:
    - "energy recycling blockchain with proof of deep learning"
    - "exploiting computation power of blockchain for biomedical image segmentation"
    - "coin ai a proof of useful work scheme for blockchain based distributed deep learning"
    - "proof of search combining blockchain consensus formation with solving optimization problems"
    - "scnn a general distribution based statistical convolutional neural network with application to video object detection"
    - "privacy aware cost effective scheduling considering non schedulable appliances in smart home"
    - "real time adversarial attacks"
    - "measuring human perception to improve handwritten document transcription"

Connected through hyperedge HE-2 (induced by source paper "a taxonomic approach to understanding emerging blockchain identity management systems"):
  with members:
    - "a decentralised digital identity architecture"
    - "verifiable anonymous identities and access control in permissioned blockchains"
    - "on the practicality of a smart contract pki"
    - "certledger a new pki model with certificate transparency based on blockchain"
    - "a privacy preserving system for data ownership using blockchain and distributed databases"
    - "blockpki an automated resilient and transparent public key infrastructure"
    - "a first look at identity management schemes on the blockchain"
    - "coconut threshold issuance selective disclosure credentials with applications to distributed ledgers"

Connected through hyperedge HE-3 (induced by source paper "blockchains and distributed databases a twin study"):
  with members:
    - "atomic commitment across blockchains"
    - "cross chain deals and adversarial commerce"
    - "blockchain meets database design and implementation of a blockchain relational database"
    - "chain of trust can trusted hardware help scaling blockchains"
    - "performance evaluation of the quorum blockchain platform"
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "towards scaling blockchain systems via sharding"
    - "atomic cross chain swaps"

Connected through hyperedge HE-4 (induced by source paper "blockchains a systematic multivocal literature review"):
  with members:
    - "hyperledger fabric a distributed operating system for permissioned blockchains"
    - "blockchains consensus protocols in the wild"
    - "adding concurrency to smart contracts"
    - "a blockchain based decentralized system for proper handling of temporary employment contracts"
    - "an empirical analysis of smart contracts platforms applications and design patterns"
    - "rollback and forking detection for trusted execution environments using lightweight collective memory"
    - "blockbench a framework for analyzing private blockchains"
    - "untangling blockchain a data processing view of blockchain systems"

Connected through hyperedge HE-5 (induced by source paper "exploiting computation power of blockchain for biomedical image segmentation"):
  with members:
    - "energy recycling blockchain with proof of deep learning"
    - "scnn a general distribution based statistical convolutional neural network with application to video object detection"
    - "nnu net self adapting framework for u net based medical image segmentation"
    - "quantization of fully convolutional networks for accurate biomedical image segmentation"
    - "ct realistic lung nodule simulation from 3d conditional generative adversarial networks for robust lung segmentation"
    - "suggestive annotation a deep active learning framework for biomedical image segmentation"
    - "3d u net learning dense volumetric segmentation from sparse annotation"
    - "v net fully convolutional neural networks for volumetric medical image segmentation"

Connected through hyperedge HE-6 (induced by source paper "properties of decentralized consensus technology why not every blockchain is a blockchain"):
  with members:
    - "decentralization in bitcoin and ethereum networks"
    - "sharvot secret share based voting on the blockchain"
    - "stampery blockchain timestamping architecture bta version 6"
    - "casper the friendly finality gadget"
    - "bitcoin ng a scalable blockchain protocol"
    - "decentralized trusted timestamping using the crypto currency bitcoin"
    - "cryptocurrencies without proof of work"
    - "majority is not enough bitcoin mining is vulnerable"

Connected through hyperedge HE-7 (induced by source paper "towards blockchain enabled searchable encryption"):
  with members:
    - "ekiden a platform for confidentiality preserving trustworthy and performant smart contracts"
    - "exploring the attack surface of blockchain a systematic overview"

Connected through hyperedge HE-8 (induced by source paper "empowering artists songwriters musicians in a data cooperative through blockchains and smart contracts"):
  with members:
    - "towards an open and scalable music metadata layer"

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)