Sign a message with your wallet key

One way to prove ownership of a wallet is to sign a message. This can be done with the polkadot website

Import your wallets, and choose the wallet you would like to sign the message with.

Here, the wallet rao has signed the message "I like taostats." To sign this message, the woner has to enter their wallets apssword. So only the owner of the wallet can create the signature.

Decrypting the signature

The other party has your wallet address, and the signature.

Click the verify tab from the link above.

The green checkmark indicates success!

Whoever created that signature has possession of the wallet.