Assumption Diversification
Most deployed post-quantum cryptography rests on structured lattice assumptions. If those assumptions weaken, the fallback portfolio matters. This direction studies code-based and alternative-assumption primitives, and the analysis of cryptographic monoculture risk as a portfolio problem.
The first wave of post-quantum standards leans heavily on structured lattices: Module-LWE and Module-SIS underpin both ML-KEM and ML-DSA. That concentration is efficient, and it is also a correlated risk. A single cryptanalytic advance against the structured-lattice family would not weaken one deployed scheme but most of them at once.
This direction treats that exposure the way a portfolio manager treats correlation: not by predicting which assumption breaks, but by holding positions whose failure modes are as independent as the state of the art allows. Code-based encryption (the McEliece line and its modern descendants) is the first hedge studied here, alongside hash-based signatures already standardized in SLH-DSA.
Working questions
- How independent, really, are the leading “alternative” assumptions from the structured-lattice family — and from each other?
- What is the deployment cost of carrying a code-based fallback in parallel, measured in bytes, code size, and operational complexity?
- Can monoculture risk be stated quantitatively enough to inform a concrete hedging decision, rather than as a slogan?
Publications in this direction
- Sampling Module-LWE Instances: A Reference Reproduction
A small, readable reference that samples Module-LWE instances over a power-of-two cyclotomic ring, as a fixture for size and timing experiments.