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: "pitfalls in designing zero effort deauthentication opportunistic human observation attacks"
  Abstract: Deauthentication is an important component of any authentication system. The widespread use of computing devices in daily life has underscored the need for zero-effort deauthentication schemes. However, the quest for eliminating user effort may lead to hidden security flaws in the authentication schemes. As a case in point, we investigate a prominent zero-effort deauthentication scheme, called ZEBRA, which provides an interesting and a useful solution to a difficult problem as demonstrated in the original paper. We identify a subtle incorrect assumption in its adversary model that leads to a fundamental design flaw. We exploit this to break the scheme with a class of attacks that are much easier for a human to perform in a realistic adversary model, compared to the na\"ive attacks studied in the ZEBRA paper. For example, one of our main attacks, where the human attacker has to opportunistically mimic only the victim's keyboard typing activity at a nearby terminal, is significantly more successful compared to the na\"ive attack that requires mimicking keyboard and mouse activities as well as keyboard-mouse movements. Further, by understanding the design flaws in ZEBRA as cases of tainted input, we show that we can draw on well-understood design principles to improve ZEBRA's security.

Connected through hyperedge HE-1 (induced by source paper "short range audio channels security survey of mechanisms applications and research challenges"):
  with members:
    - "perils of zero interaction security in the internet of things"
    - "a survey on context based co presence detection techniques"
    - "doubleecho mitigating context manipulation attacks in copresence verification"
    - "survey and systematization of secure device pairing"
    - "continuous authentication for voice assistants"
    - "dolphinattack inaudible voice commands"
    - "a survey on homomorphic encryption schemes theory and implementation"
    - "don t skype type acoustic eavesdropping in voice over ip"

Connected through hyperedge HE-2 (induced by source paper "survey and systematization of secure device pairing"):
  with members:
    - "demo of bandana body area network device to device authentication using natural gait"
    - "rapid user transparent and trustworthy device pairing for d2d enabled mobile crowdsourcing"
    - "walk unlock zero interaction authentication protected with multi modal gait biometrics"
    - "challenges in mobile multi device ecosystems"
    - "when theory and reality collide demystifying the effectiveness of ambient sensing for nfc based proximity detection by applying relay attack data"
    - "stash securing transparent authentication schemes using prover side proximity verification"
    - "contextual proximity detection in the face of context manipulating adversaries"
    - "on covert acoustical mesh networks in air"

Connected through hyperedge HE-3 (induced by source paper "waca wearable assisted continuous authentication"):
  with members:
    - "6thsense a context aware sensor based attack detector for smart devices"
    - "a survey on homomorphic encryption schemes theory and implementation"

Connected through hyperedge HE-4 (induced by source paper "assentication user deauthentication and lunchtime attack mitigation with seated posture biometric"):
  with members:
    - "fadewich fast deauthentication over the wireless channel"

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)