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 "difficulties of timestamping archived web pages"):
  Abstract: We show that state-of-the-art services for creating trusted timestamps in blockchain-based networks do not adequately allow for timestamping of web pages. They accept data by value (e.g., images and text), but not by reference (e.g., URIs of web pages). Also, we discuss difficulties in repeatedly generating the same cryptographic hash value of an archived web page. We then introduce several requirements to be fulfilled in order to produce repeatable hash values for archived web pages.

Includes members:
  Member "impact of uri canonicalization on memento count":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "a framework for aggregating private and public web archives")
  Member "rules of acquisition for mementos and their content":
    also connected through other hyperedges:
      (none)
  Member "decentralized trusted timestamping using the crypto currency bitcoin":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "the security reference architecture for blockchains towards a standardized model for studying vulnerabilities threats and defenses")
  Member "a framework for evaluation of composite memento temporal coherence":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "supporting web archiving via web packaging")
  Member "an evaluation of caching policies for memento timemaps":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "a framework for aggregating private and public web archives")
  Member "memento time travel for the web":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "archive assisted archival fixity verification framework")
  Member "transparent format migration of preserved web content":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "requirements for digital preservation systems a bottom up approach")

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.DL(Digital Libraries)