human: Given a node-centered hypergraph: <hypergraph>, where nodes represent authors and hyperedges represent groups of authors who co-authored the same paper.

Details of the hypergraph:
Center node: "Securing a B+tree for Use with Secret-Shared Databases"
  Abstract: Information revelations from databases may result not only from intrusions by external attackers but also from malicious actions by employees and even database administrators. A promising new approach to solving this problem is the use of secret-shared databases. In this approach, information is divided into unreadable snippets, and the snippets are stored in separate subdatabases, thereby making it difficult for external and internal attackers to steal the original information. A secret-shared database is secure unless k or more database administrators collude, where k is a predefined threshold. Any query that is executable for a conventional database is executable for the corresponding secret-shared database. However, retrieval (i.e., selection) of a record from a secret-shared database has a time complexity of O(m), where m is the number of records stored in the database. We used a B+tree, which is a standard data structure for efficiently retrieving data from conventional databases, to develop a secret-shared B+tree that enables data retrieval from secret-shared databases with O(logm) time complexity while maintaining the security provided by secret sharing.

Connected through hyperedge HE-1 (induced by source paper "More Efficient Constant-Round Multi-party Computation from BMR and SHE"):
  with members:
    - "Authenticating Computation on Groups: New Homomorphic Primitives and Applications"
    - "A Secure Obfuscator for Encrypted Blind Signature Functionality"
    - "On Obfuscation with Random Oracles"
    - "Graph-Induced Multilinear Maps from Lattices"
    - "Blazing Fast 2PC in the Offline/Online Setting with Security for Malicious Adversaries"
    - "Non-Interactive Secure Computation Based on Cut-and-Choose"
    - "Efficient Secure and Verifiable Outsourcing of Matrix Multiplications"
    - "Rational Secure Two-party Computation in Social Cloud"

Question: Please tell me which research area the center author belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Computer science