Hyperledger Global Forum 2022

Maybe you want to put your credentials on the blockchain, but you're worried about privacy. You don't want to be tracked every time you present your identity. One option is something called an accumulator. Accumulators use a short piece of data to represent a list of credentials, with users doing most of the work to maintain extra data to prove that they have a valid credential. Accumulators can easily issue and revoke credentials, and can be constructed with high privacy guarantees and little trust required. However, this makes them slow. Many variants on the classic constructions have been proposed to improve performance, but these compromise privacy and trust, sometimes in subtle ways. In this talk Sam will give an overview of what accumulators are, how they can be used, and describe some fundamental limits on the trade-off between privacy and efficiency. He and collaborators are working on a new approach which uses distributed trust to avoid some of the theoretical limits and create a completely anonymous accumulator that should be faster than previous methods.