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 "a case of collusion a study of the interface between ad libraries and their apps"):
  Abstract: A growing concern with advertisement libraries on Android is their ability to exfiltrate personal information from their host applications. While previous work has looked at the libraries' abilities to measure private information on their own, advertising libraries also include APIs through which a host application can deliberately leak private information about the user. This study considers a corpus of 114,000 apps. We reconstruct the APIs for 103 ad libraries used in the corpus, and study how the privacy leaking APIs from the top 20 ad libraries are used by the applications. Notably, we have found that app popularity correlates with privacy leakage; the marginal increase in advertising revenue, multiplied over a larger user base, seems to incentivize these app vendors to violate their users' privacy.

Includes members:
  Member "longitudinal analysis of android ad library permissions":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "pyronia redesigning least privilege and isolation for the age of iot")
  Member "adsplit separating smartphone advertising from applications":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "an empirical study of usages updates and risks of third party libraries in java projects")

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)