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: "gnss based positioning attacks and countermeasures"
  Abstract: Increasing numbers of mobile computing devices, user-portable, or embedded in vehicles, cargo containers, or the physical space, need to be aware of their location in order to provide a wide range of commercial services. Most often, mobile devices obtain their own location with the help of Global Navigation Satellite Systems (GNSS), integrating, for example, a Global Positioning System (GPS) receiver. Nonetheless, an adversary can compromise location-aware applications by attacking the GNSS-based positioning: It can forge navigation messages and mislead the receiver into calculating a fake location. In this paper, we analyze this vulnerability and propose and evaluate the effectiveness of countermeasures. First, we consider replay attacks, which can be effective even in the presence of future cryptographic GNSS protection mechanisms. Then, we propose and analyze methods that allow GNSS receivers to detect the reception of signals generated by an adversary, and then reject fake locations calculated because of the attack. We consider three diverse defense mechanisms, all based on knowledge, in particular, own location, time, and Doppler shift, receivers can obtain prior to the onset of an attack. We find that inertial mechanisms that estimate location can be defeated relatively easy. This is equally true for the mechanism that relies on clock readings from off-the-shelf devices; as a result, highly stable clocks could be needed. On the other hand, our Doppler Shift Test can be effective without any specialized hardware, and it can be applied to existing devices.

Connected through hyperedge HE-1 (induced by source paper "message time of arrival codes a fundamental primitive for secure distance measurement"):
  with members:
    - "uwb ed distance enlargement attack detection in ultra wideband"
    - "on the security of carrier phase based ranging"

Connected through hyperedge HE-2 (induced by source paper "risk assessment of autonomous vehicles using bayesian defense graphs"):
  with members:
    - "dag based attack and defense modeling don t miss the forest for the attack trees"

Connected through hyperedge HE-3 (induced by source paper "real time rejection and mitigation of time synchronization attacks on the global positioning system"):
  with members:
    - "vulnerability analysis of smart grids to gps spoofing"
    - "gnss signal authentication via power and distortion monitoring"
    - "doubly robust smoothing of dynamical processes via outlier sparsity constraints"

Connected through hyperedge HE-4 (induced by source paper "time synchronization attack in smart grid part ii cross layer detection mechanism"):
  with members:
    - "combating false reports for secure networked control in smart grid via trustiness evaluation"

Connected through hyperedge HE-5 (induced by source paper "secure neighbor position discovery in vanets"):
  with members:
    - "towards provable secure neighbor discovery in wireless networks"
    - "secure vehicular communication systems design and architecture"
    - "secure neighbor discovery in wireless networks formal investigation of possibility"

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)