How does one create a proper signature for a given message using Bitcoin private keys?

I have an input address of




I want to sign message:


I convert it to hex:


I feed it to a signing function of ECDSA library that uses secp256k1, and I get two outputs,

r = D16A44BF1095FB7D517C7C4DD6A51E3EFD29548C5CAD8CA4AB763946D02AE0E8 
s = 2AB3E674B788804B87CED50619A1EFA267E17D20C016D0779BC3203D40E8105D 

If I marshal it with DER/asn1 as a list of Big Integers, I get a result of:


If I marshal them as a list of byte arrays, I get


if I marshal them as one long byte array, I get 0WpEvxCV+31RfHxN1qUePv0pVIxcrYykq3Y5RtAq4Ogqs+Z0t4iAS4fO1QYZoe+iZ+F9IMAW0HebwyA9QOgQXQ==

None of them appear to work as signatures when I try to verify the message signature using tools like http://brainwallet.org/#verify .

How do I properly sign messages using Bitcoin private keys to be compatible with BitcoinQT?

  • 2
    The ultimate documentation is the source... Commented Nov 15, 2013 at 16:46
  • 1
    What's wrong with signmessage <bitcoinaddress> <message>?
    – KJ O
    Commented Apr 5, 2014 at 20:19
  • Have you found the signing algorithm? I tried doubleSha(msg.getBytes) (in Java). Verification fails.
    – Jus12
    Commented Dec 20, 2017 at 17:08
  • 2
    For heavens sake the question is asked so things can be done manually with out using any programs such as bitcoin-qt its a technical question ! The user wants to sign a tx manually and check with bitcoin-qt or cli to make sure he signed is correct !
    – f4r4
    Commented Mar 27, 2018 at 18:24

2 Answers 2


Using bitcoind and bitcoin-cli you can do it as follows:

bitcoin-cli signmessage 1DiWX6p3FdHPZqN88vMeGVXSwAQ1h7BeVj 'Hello world!'

In Bitcoin-qt

enter image description here enter image description here

Or you can do it in blockchain.info/wallet by clicking the menu above your addresses.

No need to do it manually.

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