Quote from: BlackHatCoiner on Today at 05:08:09 PM

Quote from: iamonlinenow on Today at 04:27:52 PM

That means the creator can't sign with the 'r' key, similar to the 1LZtnC7Ck37V9uLGGXFmaVkeaLyzFLvf6W case.

This means the creator can't sign from any of the addresses. Only from the one whose public key is equal with the sum of the addresses' public keys.

If the creator is Satoshi than he can sign with 2 keys. One key is the 'relative' key and the other one the 'absolute' key.

Let me explain it with 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa (Satoshi's receiving address for the coinbase transaction of the genesis block).
We assume that the private key for that address is k_Sat=10000. Satoshi creates a 'relative' key with k_rel=100, so the 'absolute' key would have the private key k_abs=10100. He publishes the 2 public keys ('relative' and 'absolute') with signatures and we can check that they are valid and that he is the owner of 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa.

In our case (OP) we only have the 'relative' key signature. The second one ('absolute' key signature) is missing.

Quote from: o_e_l_e_o on Today at 07:24:19 PM

The good way is to sign a message from 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa

Quote from: BlackHatCoiner on Today at 05:08:09 PM

why not just give you a signed message from the - 1C7X4UWpSa4GteWHaRBm49fMCC2SNvJQF - which supposedly a Satoshi's address?

Maybe for security reasons. Let's say he wants to communicate with us and wants to sign the messages. For each signature he would need the private key k_Sat. With the above example he could prove it only once and then use the private key k_abs for all signatures. If hacked, he could create a new k_absnew.