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 analysis of instant messenger applications on android devices"
  Abstract: modern day Smartphone's have built in apps like "WhatsApp & Viber" which allow users to exchange instant messages, share videos, audio's and images via Smartphone's instead of relying on their desktop Computers or laptop thereby increasing the portability and convenience for a layman smart phone user. An Instant Messenger (IM) can serve as a very useful yet very dangerous platform for the victim and the suspect to communicate. The increased use of Instant messengers on Android phones has turned to be the goldmine for mobile and computer forensic experts. Traces and Evidence left by applications can be held on Android phones and retrieving those potential evidences with right forensic technique is strongly required. This paper focuses on conducting forensic data analysis of 2 widely used IMs applications on Android phones: WhatsApp and Viber. 5 Android phones were analyzed covering 3 different versions of Android OS: Froyo (2.2), GingerBread (2.3.x) and Ice- Cream Sandwich (4.0.x). The tests and analysis were performed with the aim of determining what data and information can be found on the device's internal memory for instant messengers e.g. chat messaging logs and history, send & received image or video files, etc. Determining the location of data found from FileSystem Extraction of the device was also determined. The experiments and results show that heavy amount of potential evidences and valuable data can be found on Android phones by forensic investigators.

Connected through hyperedge HE-1 (induced by source paper "analyzing and characterizing political discussions in whatsapp public groups"):
  with members:
    - "understanding the characteristics of internet short video sharing youtube as a case study"

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"
    - "forensic taxonomy of popular android mhealth apps"
    - "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"

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)