I'm fairly certain it isn't possible. If you can detect, with high confidence, that an entity received a message and that an entity sent a message, timing attac

I'm fairly certain it isn't possible. If you can detect, with high confidence, that an entity received a message and that an entity sent a message, timing attacks can be done. The traditional means to prevent this involves sending dummy traffic, introducing unpredictable latency, or using some sort of broadcast to conceal the exact receiver. None of those things are practical for a low-latency proxy. It's been a couple years since I studied this, so I might be wrong.