Decentralized Private Stream Aggregation from Lattices

Paper i proceeding, 2024

As various industries and government agencies increasingly seek to build quantum computers, the development of post-quantum constructions for different primitives becomes crucial. Lattice-based cryptography is one of the top candidates for constructing quantum-resistant primitives. In this paper, we propose a decentralized Private Stream Aggregation (PSA) protocol based on the Learning with Errors (LWE) problem. PSA allows secure aggregation of time-series data over multiple users without compromising the privacy of the individual data. In almost all previous constructions, a trusted entity is used for the generation of keys. We consider a scenario where the users do not want to rely on a trusted authority. We, therefore, propose a decentralized PSA (DPSA) scheme where each user generates their own keys without the need for a trusted setup. We give a concrete construction based on the hardness of the LWE problem both in the random oracle model and in the standard model.