Indistinguishability obfuscation allows one to turn a program unintelligible, without altering its functionality. Because it captures the power of most known cryptographic primitives and enables new ones, obfuscation is often referred to as being crypto-complete. In this work we investigate constructions of indistinguishability obfuscation, whose security can be reduced from potentially hard problems over lattices. Compared to other candidates, a purely lattice-based obfuscator has the advantage of being based on a single source of hardness and being plausibly post-quantum, enabling many applications in quantum cryptography.
We propose a new construction of lattice-based obfuscation whose security relies on an instance-independent assumption over lattices called the Equivocal Learning with Errors (LWE) assumption, which is closely related to the recently introduced Evasive LWE assumption. Our main technical ingredient is a new statistical trapdoor algorithm for equivocating LWE secrets over lattices with exceptionally short vectors, which may be of independent interest.
Ivy K. Y. Woo is a PhD student in cryptography at Aalto University, Finland since 2022. Her research focuses on cryptographic constructions from lattices. Recently she is working on advanced encryption such as attribute-based encryption. More generally, she is interested in constructing cryptographic objects from an algebraic perspective.