Project Topics

Here is a listing of possible topics and research questions for the course project. For each topic area, I list a few papers that could serve as the starting point for a survey as well as some open questions that could be the starting point for a research-based project. You are welcome to choose one of the directions listed here or propose your own direction.

Complexity of Lattice Problems

Possible Directions
  • NP-hardness of GapSVP under a deterministic reduction under the \(\ell_2\) norm.

  • NP-hardness of GapSVP under polynomial-time reductions for a super-constant approximation factor

  • Classical worst-case hardness for LWE that subsumes the quantum reduction

  • Fine-grained hardness of GapSVP (e.g., ruling out a \( 2^{n / 10} \) algorithm for GapSVP under SETH); see also this blog post

Fully Homomorphic Encryption

Constructions

Possible Directions
  • Fully homomorphic encryption from LWE without making an additional circular security assumption

  • Homomorphic signatures with short public parameters (without random oracles)

  • Fully homomorphic signatures from lattices

Applications

Possible Directions
  • Better concrete efficiency of cryptographic protocols like PSI, PIR, ORAM using FHE composition

Homomorphic Secret Sharing

Foundations

Possible Directions
  • FSS/HSS for multiple parties (more than 2) from lattices without FHE

Applications

Possible Directions
  • Concretely-efficient multi-party constructions (for restricted functionalities)

Proof Systems

Possible Directions
  • Publicly-verifiable SNARG from lattice-based assumptions (without random oracles)

  • Cryptanalysis of lattice-based linear-only assumptions

Lattice-Based PRFs

Possible Directions
  • Worst-case hardness for LWR with polynomial modulus and an unbounded number of samples

  • Lattice-based PRF computable in \( \mathsf{NC}^1 \) from LWE with a polynomial modulus