Could you sign a message from the address which one you frequently used on the forum years ago?
Sure why not ?
wait a minute ...
Edit: Signing a message from the BTC address i used 9 years ago in this forum proving I am the sole owner of the account
-----BEGIN BITCOIN SIGNED MESSAGE-----
This is codehtcmail (U=815571) on this day 13th/April/2025 who is still in control of this account and that no one else is trying to acquire a loan through my account except me. My usdt deposit address for BEP20 is 0xc61435c1976Db558a07D2331C86F39d722D1f252 on which the loan is going to be sent.
-----BEGIN SIGNATURE-----
1AAdRQ8Z1uGdBtBTPAR4QFrxB6USw8gwuH
HP6T+oMckHB8W/BIo5ELZsJ+pZm/338W9MUl+cMRGdfPGtDMdnAwFGV3ltSMq5jHbLpfni00Re06G8buxKmiYms=
-----END BITCOIN SIGNED MESSAGE-----