I was reading about Kadcast expecting a privacy story and found the opposite tension.
On the surface it sounds like an obfuscation layer — structured routing, not flooding, so surely origin gets buried in the noise. But when I traced how it actually works, Kadcast forwards messages along deterministic multicast paths based on XOR distance in a Kademlia-style overlay. That's built for bandwidth efficiency, not anonymity.
That's where it got interesting. Random gossip is messy, but the mess is what makes tracing origin harder. Kadcast's structure is the opposite — predictable paths mean a node's position in the overlay is fairly consistent. If you know the topology, you can reason about propagation patterns more easily than with flood-based gossip.
So the "privacy" people associate with Kadcast isn't really coming from the network layer at all. It's Phoenix and the ZK circuits doing that work at the transaction level. Kadcast's job is just getting votes and blocks around Succinct Attestation committees fast and cheap.
Not a flaw exactly — just a different design goal than I assumed going in. Still wondering whether structured overlays like this create any metadata exposure that gossip-based chains don't have to think about.