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: "what s in a downgrade a taxonomy of downgrade attacks in the tls protocol and application protocols using tls"
  Abstract: A number of important real-world protocols including the Transport Layer Security (TLS) protocol have the ability to negotiate various security-related choices such as the protocol version and the cryptographic algorithms to be used in a particular session. Furthermore, some insecure application-layer protocols such as the Simple Mail Transfer Protocol (SMTP) negotiate the use of TLS itself on top of the application protocol to secure the communication channel. These protocols are often vulnerable to a class of attacks known as downgrade attacks which targets this negotiation mechanism. In this paper we create the first taxonomy of TLS downgrade attacks. Our taxonomy classifies possible attacks with respect to four different vectors: the protocol element that is targeted, the type of vulnerability that enables the attack, the attack method, and the level of damage that the attack causes. We base our taxonomy on a thorough analysis of fifteen notable published attacks. Our taxonomy highlights clear and concrete aspects that many downgrade attacks have in common, and allows for a common language, classification, and comparison of downgrade attacks. We demonstrate the application of our taxonomy by classifying the surveyed attacks.

Connected through hyperedge HE-1 (induced by source paper "towards forward secure internet traffic"):
  with members:
    - "does www mean better transport layer security"

Connected through hyperedge HE-2 (induced by source paper "dstc dns based strict tls configurations"):
  with members:
    - "a metapolicy framework for enhancing domain expressiveness on the internet"
    - "on the feasibility of fine grained tls security configurations in web browsers based on the requested domain name"

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)