Quantum Cryptography

My research asks how quantum information changes the foundations and capabilities of cryptography: the assumptions we need, the tasks we can achieve, and the guarantees we can verify.

For an accessible introduction, see Quanta’s article on our work or my recorded talks and tutorials.

Foundations and assumptions

What assumptions does cryptography need in a quantum world? My work builds commitments and secure computation from quantum notions of one-wayness and assumptions connected to quantum advantage. More recent work examines the limits of proposed routes to quantum cryptography beyond classical one-way functions.

Certified deletion and unclonability

Quantum information can make it possible to certify that a secret has been deleted, even when it was initially protected only by computational hardness. My work develops this guarantee for encryption and software, studies public verification of deletion, and explores proofs that cannot be copied.

Verification and certified randomness

How can a classical verifier check quantum behavior? My work studies verification that preserves a quantum witness and the power of oblivious state preparation. Recent results certify randomness in the quantum random oracle model, including unconditional security against adversaries making subexponentially many queries.

Secure quantum computation

Secure computation lets mutually distrustful parties compute together while protecting their private inputs. My work shows that quantum-hard one-way functions suffice for general secure computation, and studies how interaction, entanglement, and zero-knowledge proofs shape what protocols can achieve.