Believe me, if Satoshi returns, he will be the talk of the hour and you will find everyone trying to verify his identity, so all you have to do is search here.
The message is signed with the private key. Anyone who has access to the private key can sign the message. Therefore, you must maintain the security of your private key and sign the message in a form that cannot be used in the future by mentioning the name, the date, the purpose of the message, the validity of the message, and then any change in The wording of the message with even one comma will make the resulting signature being incorrect.