Ensure the user is the actual the owner of the bitcoin address they're transacting in about server HOT 4 CLOSED

Has to be part of the blockchain rules

from server.

Trying to find an easy way that would work for people who use multisig bitcoin wallets - e.g. Electrum with 2FA, which is a common setup. If I don't find a better way, we'll use the prove-by-message way, with the TXID that moved the funds to the PZ as the message.

from server.

We have an initial proof-of-ownership mechanism now - a payment/withdrawal has to be submitted with the deposit transaction ID signed via the private key of the depositor.

Of course, once this has been done once, the proof-of-ownership is visible for all to copy and use, so this is only the first step towards solving this.

from server.

Note - the current tentative plan is to for each proof-of-ownership to be done as follows.

I. Get the initial value:
I.1. If it's the first proof - the prover's first bitcoin deposit transaction ID to this Payment Zone
I.2. Otherwise - the previous proof

II. Sign what you got in the previous step the prover's private key. That's your proof-of-ownership.

from server.