Bitcoin Core - Peer ID

[Tolido12]

Hi all,

I am new in bitcoin development. I compiled and installed bitcoin core 0.21. It is up and running, all blocks are downloaded.

I am sensitive about the privacy of the transactions I submit to the network. I use tor. Is there any peer-id which ca be used to associate all the transaction I insert to the network? Say, I inserted two transactions with txid A and B which involves address xxx and yyy within short period of time. Can anyone tell addresses xxx and yyy are related to the same peer?

Thanks in advance.

[1715061614]

1715061614

[1715061614]

1715061614

[1715061614]

1715061614

[1715061614]

1715061614

[DannyHamilton]

Hi all,

I am new in bitcoin development. I compiled and installed bitcoin core 0.21. It is up and running, all blocks are downloaded.

I am sensitive about the privacy of the transactions I submit to the network. I use tor. Is there any peer-id which ca be used to associate all the transaction I insert to the network? Say, I inserted two transactions with txid A and B which involves address xxx and yyy within short period of time. Can anyone tell addresses xxx and yyy are related to the same peer?

Thanks in advance.

If they try hard enough, and if you aren't careful enough about keeping xxx and yyy from participating in any linking transactions, then yes, or maybe. But, that's true regardless of whether you are using TOR, or whether the transactions are within a short period of time or not.

It has nothing to do with your IP, or any peer-id (not sure what you mean by that), or the computer(s) you are using, or your location. It's simply a matter of how transactions are built and recorded. Without proper care, it is possible to create transactions that will link addresses together in ways that allow others to infer that the same person (or group, or business, or entity) might be in control of both addresses.

[ranochigo]

Each peer or full node doesn't have unique ID. Since Bitcoin uses gossip protocol, the only way to link transaction X and Y (without inspecting blockchain/transaction itself) is by sybil attack where attacker runs lots of nodes to find out which node broadcast the transaction for first time.

To determine whether a transaction originates from a specific node with absolute certainty, the nodes would have to be connected exclusively to you or have a MITM attack in place to capture the packets. Bitcoin Core does try to prevent this by limiting the connections to each block of IP, since attackers can easily purchase IPs in the same block relatively inexpensively.

There were concerns about deanonymizing attacks on Bitcoin nodes operated on Tor but that is fairly old and easily mitigated by connecting only to onion nodes. If you were to allow incoming connections, ensure that Bitcoin Core is binded to your Tor instance and not your clearnet IP. Bitcoin Core is pretty good at ensuring privacy (barring user behaviors and onchain linking), there is a randomized delay with inv messages which helps to make it harder for people to determine if the transaction originates from your node.