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: "An Improved Compression Technique for Signatures Based on Learning with Errors"
  Abstract: We present a new approach to the compression technique of Lyubashevsky et al. [17,13] for lattice-based signatures based on learning with errors (LWE). Our ideas seem to be particularly suitable for signature schemes whose security, in the random oracle model, is based on standard worst-case computational assumptions. Our signatures are shorter than any previous proposal for provably-secure signatures based on standard lattice problems: at the 128-bit level we improve signature size from (more than) 16500 bits to around 9000 to 12000 bits.

Connected through hyperedge HE-1 (induced by source paper "High-Speed Signatures from Standard Lattices"):
  with members:
    - "Compact McEliece Keys from Goppa Codes"
    - "Fast Cryptographic Primitives and Circular-Secure Encryption Based on Hard Learning Problems"

Connected through hyperedge HE-2 (induced by source paper "Fast Cryptographic Primitives and Circular-Secure Encryption Based on Hard Learning Problems"):
  with members:
    - "Key-dependent Message Security under Active Attacks--BRSIM/UC-Soundness of Symbolic Encryption with Key Cycles"
    - "High-Speed Signatures from Standard Lattices"
    - "Can homomorphic encryption be practical"
    - "Low Noise LPN: KDM Secure Public Key Encryption and Sample Amplification"

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: Mathematics