Quote from: iasenko on Today at 11:08:04 AM

No need, if you sign a message from an andress that makes you the one controlling the private key
........
Posting this from your current accout is enough evidence.

Okay I got the point.

Quote from: Csmiami on Today at 11:09:06 AM

If they are giving you atemplate, yes; the most logical thing is to follow it instead of creating your own message

Well, I have my own message that I used to signed with my address. So I should have followed their template while I signed it!

Quote

Electrum seems way safer than using the privkey on an online service.... I just hope his address doesn't come from a blockchain.com wallet, because it's a bit messier to extract them

My address belongs to blockchain wallet and I have used electrum before to sign message with my address.

Thank you guys for your replies.