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: "privacy assessment of de identified opal data a report for transport for nsw"
  Abstract: We consider the privacy implications of public release of a de-identified dataset of Opal card transactions. The data was recently published at this https URL. It consists of tap-on and tap-off counts for NSW's four modes of public transport, collected over two separate week-long periods. The data has been further treated to improve privacy by removing small counts, aggregating some stops and routes, and perturbing the counts. This is a summary of our findings.

Connected through hyperedge HE-1 (induced by source paper "averaging attacks on bounded noise based disclosure control algorithms"):
  with members:
    - "diffix birch extending diffix aspen"
    - "linear program reconstruction in practice"
    - "when the signal is in the noise exploiting diffix s sticky noise"
    - "differentially private release of public transport data the opal use case"
    - "concentrated differential privacy"
    - "between pure and approximate differential privacy"
    - "calibrating data to sensitivity in private data analysis"
    - "the power of linear reconstruction attacks"

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)