ctrie-java VS PSI

Concurrent tries with non-blocking snapshots [0]

Say that you have a dataset that needs to be ordered, easily searchable, but is also updated quite frequently. Fast accesses are a pain if you decide to use traditional read-write locks.

Ctries are entirely lock-free, thus there is no waiting for your read operations when an update is happening, i.e. you run lookups on snapshots while updates happen.

They are also a lot of fun to implement, especially if you aren't familiar with lock-free algorithms! I did learn a lot doing it myself [1]

[0] http://aleksandar-prokopec.com/resources/docs/ctries-snapsho...

[1] https://github.com/mabeledo/ctrie-java

There are other techniques that aren't generally included in the "Zero Knowledge Proofs" set of techniques that are perhaps more practical for general development.

For example, I fine private set intersection[1] as implemented by OpenMined a really useful primative a bunch of privacy enhancing applications can be built on top of.

My colleagues and I recently published a pre-print[2] showing how to use this for sharing locations you and another person have had in common, without being able to see other locations. The paper talks about a social network built around this but I also think there are useful applications in things like real-world games (scavenger hunts etc)

[1] https://github.com/OpenMined/PSI/blob/master/private_set_int...

[2] https://arxiv.org/abs/2210.01927

I came here to say Golomb compressed sets except now I see it's part of the question!

They are used by default in the OpenMined implementation of Private Set Intersection[1] - a multi-party computation technique.

[1] https://github.com/OpenMined/PSI/blob/master/private_set_int...

I was using OpenMinded/PSI exploring some PSI implementations, but I would like a way for the server to know the intersection size. Say Signal wants to calculate the average number of users from one person's address book (or whatever).