Signing a Bitcoin message is a very easy process
A cool function of Bitcoin is its message signing and verification feature. I’ll use the Satoshi client on a Mac as the example but the same functions are available in the wallet at blockchain.info and in any decent Bitcoin client.
In the Satoshi client, go to the “Receive Coins” tab. At the bottom, you’ll see an option that says, “Sign Message” (you can also go to File > Sign Message). Enter the Bitcoin address that you own that initiated the transaction (that’s the address to the left of the green arrow in the transaction record mentioned earlier) into the address form. Write your message and then hit the “Sign Message” button.
The signature generated is unique to the address and to the message. Send your address, the message and the signature to the buyer. They’ll take your info and enter it into the “Verify Message” function of Bitcoin, usually located somewhere near the “Sign Message” button.
Sign the Bitcoin message being offline
FULL NODE wallet
- bitcoin unlimited
- bitcoin classic
SPV WALLET (Simplified Payment Verification)
- ledger nano s
- Github signature tool (browser based) – https://github.com/ReinProject/bitcoin-signature-tool
How to generate public & private Bitcoin keys
- Bitaddress – https://www.bitaddress.org
How to sign messages with different bitcoin wallets?
if you are useing another wallet please google how to sign a message with that wallet
if you are using a wallet that doesn’t sign transactions then you will have to import your private keys into one of the wallets above.