I'm looking for a data structure similar to a dynamic accumulator that has the following properties:
- Small size: ideally under 100 bytes for the accumulator, and also under 100 bytes for witnesses
- Constant-time updates (add, remove) that can be performed publicly
- Constant witnesses - meaning, a witness for a value in the accumulator does not need to be recomputed when the accumulator is updated
Is there such a data structure out there?
One potential simplification: all accumulated values are 3-tuples $(P,d,S)$, where $P$ is a public key, $d$ is some arbitrary data, and $S$ is a BLS signature of $P||d$ which can be verified against $P$.