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: "sok cryptographically protected database search"
  Abstract: Protected database search systems cryptographically isolate the roles of reading from, writing to, and administering the database. This separation limits unnecessary administrator access and protects data in the case of system breaches. Since protected search was introduced in 2000, the area has grown rapidly; systems are offered by academia, start-ups, and established companies. #R##N#However, there is no best protected search system or set of techniques. Design of such systems is a balancing act between security, functionality, performance, and usability. This challenge is made more difficult by ongoing database specialization, as some users will want the functionality of SQL, NoSQL, or NewSQL databases. This database evolution will continue, and the protected search community should be able to quickly provide functionality consistent with newly invented databases. #R##N#At the same time, the community must accurately and clearly characterize the tradeoffs between different approaches. To address these challenges, we provide the following contributions: #R##N#1) An identification of the important primitive operations across database paradigms. We find there are a small number of base operations that can be used and combined to support a large number of database paradigms. #R##N#2) An evaluation of the current state of protected search systems in implementing these base operations. This evaluation describes the main approaches and tradeoffs for each base operation. Furthermore, it puts protected search in the context of unprotected search, identifying key gaps in functionality. #R##N#3) An analysis of attacks against protected search for different base queries. #R##N#4) A roadmap and tools for transforming a protected search system into a protected database, including an open-source performance evaluation platform and initial user opinions of protected search.

Connected through hyperedge HE-1 (induced by source paper "timecrypt encrypted data stream processing at scale with cryptographic access control"):
  with members:
    - "jedi many to many end to end encryption and key delegation for iot"
    - "prio private robust and scalable computation of aggregate statistics"
    - "streetx spatio temporal access control model for data"
    - "efficient private statistics with succinct sketches"

Connected through hyperedge HE-2 (induced by source paper "ai enabling technologies a survey"):
  with members:
    - "the lustre storage architecture"
    - "qiniu submission to activitynet challenge 2018"
    - "moments in time dataset one million videos for event understanding"
    - "interactive supercomputing on 40 000 cores for machine learning and data analysis"
    - "this looks like that deep learning for interpretable image recognition"
    - "gazelle a low latency framework for secure neural network inference"
    - "tracking emerges by colorizing videos"
    - "robust physical world attacks on deep learning models"

Connected through hyperedge HE-3 (induced by source paper "conclave secure multi party computation on big data"):
  with members:
    - "towards practical differential privacy for sql queries"
    - "prochlo strong privacy for analytics in the crowd"
    - "scaling private record linkage using output constrained differential privacy"
    - "smcql secure querying for federated databases"
    - "quorums quicken queries efficient asynchronous secure multiparty computation"
    - "secure multi party computation in large networks"

Connected through hyperedge HE-4 (induced by source paper "oblidb oblivious query processing for secure databases"):
  with members:
    - "sgxpectre stealing intel secrets from sgx enclaves via speculative execution"
    - "obladi oblivious serializable transactions in the cloud"
    - "the pyramid scheme oblivious ram for trusted processors"
    - "stealthdb a scalable encrypted database with full sql query support"
    - "software grand exposure sgx cache attacks are practical"
    - "prochlo strong privacy for analytics in the crowd"
    - "hardidx practical and secure index with sgx"
    - "inferring fine grained control flow inside sgx enclaves with branch shadowing"

Connected through hyperedge HE-5 (induced by source paper "stealthdb a scalable encrypted database with full sql query support"):
  with members:
    - "software grand exposure sgx cache attacks are practical"
    - "malware guard extension using sgx to conceal cache attacks"
    - "hardidx practical and secure index with sgx"
    - "inferring fine grained control flow inside sgx enclaves with branch shadowing"

Connected through hyperedge HE-6 (induced by source paper "version 0 1 of the bigdawg polystore system"):
  with members:
    - "the bigdawg polystore system and architecture"
    - "computing on masked data to improve the security of big data"
    - "the vertica analytic database c store 7 years later"

Connected through hyperedge HE-7 (induced by source paper "differentially private oblivious ram"):
  with members:
    - "differential privacy as a mutual information constraint"
    - "rappor randomized aggregatable privacy preserving ordinal response"
    - "differential privacy an economic method for choosing epsilon"
    - "privacy preserving group data access via stateless oblivious ram simulation"
    - "towards practical oblivious ram"
    - "privacy preserving access of outsourced data via oblivious ram simulation"
    - "composition attacks and auxiliary information in data privacy"

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)