blockchain.info: How to sign a message from previously used addresses

[Aerospace1244]

Hello guys.
I sent money some months ago using my bitcoin wallet. So right now the payee asking me to sign a message to prove that this address is mine. I know that blockchain.info has this function but the address that I used to send the money is in used addresses list. So I don't know how to sign the message. Please help me.
There is instruction here https://support.[Suspicious link removed]/hc/en-us/articles/210353833-What-is-message-signing-and-how-can-I-do-that-
But I don't know how to use it for used addresses...
Thank you very much in advance.

[Potato Chips]

Signing a messsage is only available for imported addresses, If the address is a part of your HD wallet, then that feature won't be available. Quoting it with the link you provided:

This feature is currently only available for your Imported Addresses

But there are still ways to sign a message

1. Using some third party tools:

If the particular address is a part of your blockchain.info HD wallet, follow these steps, otherwise ignore it.

(You must have your Recovery phrase/Seed before proceeding)

First, You must get it's private key

Download this and run it offline: https://github.com/iancoleman/bip39. Paste your seed there and you will see your address/es and its corresponding private keys at the "Derived Addresses" section. To toggle between accounts, Change the number on the "account" field where 0 is your default account, it means your 2nd account will be "1" and the 3rd will be "2" and so on.. (Use Ctrl+F to easily find the address you want)

Lastly, Download this and run it offline: https://github.com/OrdinaryDude/offline-bitcoin-signer. Paste the private key, enter your message and hit "Sign"

P.S. I tested this and verified the signature through coinig

2. Importing it in another wallet and signing a message there. I recommend electrum for that

Using your seed/backup phrase:

Tutorial: https://bitcoinelectrum.com/restoring-your-standard-wallet-from-seed

*When electrum prompts you to enter your seed, Click options and tick the BIP39 Seed Box

*Please note that when importing, your funds will be accessible on both wallets which is why it's highly advisable to transfer them in a new wallet (with different seed/PK's) once the network has stabilized to avoid high fees.

Here's a tutorial to sign a message in electrum: https://www.cryptocompare.com/wallets/guides/how-to-sign-a-message-with-electrum

You can also import just one address using its private key. Use the iancoleman bip39 tool for deriving your PK's as mentioned above
Guide: https://bitcoinelectrum.com/importing-your-private-keys-into-electrum

[Aerospace1244]

Signing a messsage is only available for imported addresses, If the address is a part of your HD wallet, then that feature won't be available. Quoting it with the link you provided:

/hc/en-us/articles/210353833-What-is-message-signing-and-how-can-I-do-that-]
This feature is currently only available for your Imported Addresses

But there are still ways to sign a message

1. Using some third party tools:

If the particular address is a part of your blockchain.info HD wallet, follow these steps, otherwise ignore it.

(You must have your Recovery phrase/Seed before proceeding)

First, You must get it's private key

Download this and run it offline: https://github.com/iancoleman/bip39. Paste your seed there and you will see your address/es and its corresponding private keys at the "Derived Addresses" section. To toggle between accounts, Change the number on the "account" field where 0 is your default account, it means your 2nd account will be "1" and the 3rd will be "2" and so on.. (Use Ctrl+F to easily find the address you want)

Lastly, Download this and run it offline: https://github.com/OrdinaryDude/offline-bitcoin-signer. Paste the private key, enter your message and hit "Sign"

P.S. I tested this and verified the signature through coinig

2. Importing it in another wallet and signing a message there. I recommend electrum for that

Using your seed/backup phrase:

Tutorial: https://bitcoinelectrum.com/restoring-your-standard-wallet-from-seed

*When electrum prompts you to enter your seed, Click options and tick the BIP39 Seed Box

*Please note that when importing, your funds will be accessible on both wallets which is why it's highly advisable to transfer them in a new wallet (with different seed/PK's) once the network has stabilized to avoid high fees.

Here's a tutorial to sign a message in electrum: https://www.cryptocompare.com/wallets/guides/how-to-sign-a-message-with-electrum

You can also import just one address using its private key. Use the iancoleman bip39 tool for deriving your PK's as mentioned above
Guide: https://bitcoinelectrum.com/importing-your-private-keys-into-electrum

Thank you very much. You saved me! I was looking for this information during the last week. I wrote to the blockchain.info support they still didn't answered yet. Thank you very much! Do you think it is a good idea to mover from blockchain.info to Electrum?..

[bL4nkcode]

--snip--
Do you think it is a good idea to mover from blockchain.info to Electrum?..

That will be a good decision if you will use electrum instead of blockchain.info wallet. You can control your funds there freely especially the transaction fees unlike on blockchain wallet since there are unknown bugs with that wallet, even you will use the regular fee your transaction will have a low fee or opposite of it.

[Potato Chips]

--snip--
Do you think it is a good idea to mover from blockchain.info to Electrum?..

That will be a good decision if you will use electrum instead of blockchain.info wallet. You can control your funds there freely especially the transaction fees unlike on blockchain wallet since there are unknown bugs with that wallet, even you will use the regular fee your transaction will have a low fee or opposite of it.

Seconded! I can vouch for electrum as I've been using it for months and I haven't encountered any significant problem so far.

I just want to add that the usual rule will apply and that is to always keep your PC clean and be sure to encrypt your wallet with a strong password.

And about the fees, If you enable this two feature in electrum, it will be very unlikely for your next transactions to be stuck while blockchain.info only offers their inaccurate fee estimator 

PREVENT LOW FEE TRANSACTIONS
To prevent this sort of thing from happening in future please enable dynamic fees and replace by fee (RBF) in Electrum. Dynamic fees means that Electrum automatically sets a suitable fee based on market conditions. RBF marks a transaction as replaceable so that if it gets stuck due to low fees you can create a higher fee replacement transaction in Electrum. The increase fee option mentioned earlier is what does that.

Go to tools > preferences > fees tab and check “Use dynamic fees” and set “Propose replace-by-fee” to “Always”.

If ever you have something to ask about the wallet, you can refer to this: https://bitcoinelectrum.com or just create your thread in our Electrum board