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: "a formal proof of countermeasures against fault injection attacks on crt rsa"
  Abstract: In this article, we describe a methodology that aims at either breaking or proving the security of CRT-RSA implementations against fault injection attacks. In the specific case-study of the BellCoRe attack, our work bridges a gap between formal proofs and implementation-level attacks. We apply our results to three implementations of CRT-RSA, namely the unprotected one, that of Shamir, and that of Aumuller et al. Our findings are that many attacks are possible on both the unprotected and the Shamir implementations, while the implementation of Aumuller et al. is resistant to all single-fault attacks. It is also resistant to double-fault attacks if we consider the less powerful threat model of its authors.

Connected through hyperedge HE-1 (induced by source paper "formal analysis of crt rsa vigilant s countermeasure against the bellcore attack a pledge for formal methods in the field of implementation security"):
  with members:
    - "formal verification of a software countermeasure against instruction skip attacks"

Connected through hyperedge HE-2 (induced by source paper "formal verification of a software countermeasure against instruction skip attacks"):
  with members:
    - "electromagnetic fault injection towards a fault model on a 32 bit microcontroller"

Connected through hyperedge HE-3 (induced by source paper "countermeasures against high order fault injection attacks on crt rsa"):
  with members:
    - "formal analysis of crt rsa vigilant s countermeasure against the bellcore attack a pledge for formal methods in the field of implementation security"

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)