[politician]

"All Bitcoin transactions are published online and Internet Protocol (IP) addresses are linked to the public Bitcoin transactions."

How are IP addresses linked to the block chain?

[cwkoss]

Nodes can see which IP address sent them the transaction. Usually, this is a "supernode" connected to hundreds of others which received the transaction from someone else.

However, if you have your own supernodes and can see which node first broadcast that transaction, and you know either they sent it or are more connected to the original sender than you are.

[TazeTSchnitzel]

Well, presumably if you infiltrate the P2P network, you can catch the transaction at its source?

[politician]

Sure, but surely the block chain doesn't contain Source IP Address fields.

[TazeTSchnitzel]

That is correct.