Bitcoin node P2P traffic analysis

[andrewtoth]

@virtu

Spy nodes: Now interestingly, the bulk of inbound peers exchange only around 1MB of traffic with my node, which is too low (using traffic via my outbound connections as baseline) for them to be regular connections. All those nodes do is complete the P2P handshake, and politely reply to ping messages. Other than that, they just suck up our INV messages.

If something like Broadcast own transactions only via short-lived Tor or I2P connections by vasild · Pull Request #29415 · bitcoin/bitcoin · GitHub is merged and a majority of nodes start using it, we can disincentivize this behavior.