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: "forensic taxonomy of popular android mhealth apps"
  Abstract: Mobile health applications (or mHealth apps, as they are commonly known) are increasingly popular with both individual end users and user groups such as physicians. Due to their ability to access, store and transmit personally identifiable and sensitive information (e.g. geolocation information and personal details), they are potentially an important source of evidentiary materials in digital investigations. In this paper, we examine 40 popular Android mHealth apps. Based on our findings, we propose a taxonomy incorporating artefacts of forensic interest to facilitate the timely collection and analysis of evidentiary materials from mobile devices involving the use of such apps. Artefacts of forensic interest recovered include user details and email addresses, chronology of user locations and food habits. We are also able to recover user credentials (e.g. user password and four-digit app login PIN number), locate user profile pictures and identify timestamp associated with the location of a user.

Connected through hyperedge HE-1 (induced by source paper "a bleeding digital heart identifying residual data generation from smartphone applications interacting with medical devices"):
  with members:
    - "security incident response criteria a practitioner s perspective"
    - "forensic analysis of whatsapp messenger on android smartphones"
    - "using smartphones as a proxy for forensic evidence contained in cloud storage services"
    - "calm before the storm the challenges of cloud computing in digital forensics"

Connected through hyperedge HE-2 (induced by source paper "forensics analysis of android mobile voip apps"):
  with members:
    - "windows instant messaging app forensics facebook and skype as case studies"
    - "on the feasibility of attribute based encryption on smartphone devices"
    - "a forensically sound adversary model for mobile devices"
    - "mobile cloud forensics an analysis of seven popular android apps"
    - "conceptual evidence collection and analysis methodology for android devices"
    - "privacy risks in mobile dating apps"
    - "forensic analysis of whatsapp messenger on android smartphones"
    - "can t you hear me knocking identification of user actions on android apps via traffic analysis"

Connected through hyperedge HE-3 (induced by source paper "an android cloud storage apps forensic taxonomy"):
  with members:
    - "ubuntu one investigation detecting evidences on client machines"
    - "windows instant messaging app forensics facebook and skype as case studies"
    - "mobile cloud forensics an analysis of seven popular android apps"
    - "conceptual evidence collection and analysis methodology for android devices"

Connected through hyperedge HE-4 (induced by source paper "investigating america online instant messaging application data remnants on windows 8 1 client machine"):
  with members:
    - "a forensically sound adversary model for mobile devices"
    - "privacy risks in mobile dating apps"

Connected through hyperedge HE-5 (induced by source paper "windows instant messaging app forensics facebook and skype as case studies"):
  with members:
    - "forensics acquisition and analysis of instant messaging and voip applications"
    - "a forensically sound adversary model for mobile devices"
    - "privacy risks in mobile dating apps"
    - "an analysis of the skype peer to peer internet telephony protocol"

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.CY(Computers and Society)