How can I have a signed message with blockchain.com ? there is no option to get the signed message there
You can't create a signed message with blockchain.com using the "default" wallet addresses (ie. ones that are generated by the blockchain.com HD wallet)... but if you have an imported private key/address you can:
If you click the "Settings" icon in the top right corner and select "Wallet and Addresses:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Ftalkimg.com%2Fimages%2F2023%2F11%2F15%2Fz5iQG.png&t=665&c=vxbbHAmn1g6lMg)
Then "Imported Bitcoin Addresses" and import one:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Ftalkimg.com%2Fimages%2F2023%2F11%2F15%2Fz58YD.png&t=665&c=Ixh7b0KmwtuuzA)
Once it has been imported, you can select "More Options" -> "Sign Message":
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Ftalkimg.com%2Fimages%2F2023%2F11%2F15%2Fz5K8f.png&t=665&c=nlMjafwG1moWeA)
You can simply enter your message and click "Sign" (you'll be prompted for your 2nd password if you have one):
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Ftalkimg.com%2Fimages%2F2023%2F11%2F15%2Fz5pAZ.png&t=665&c=7FNiQ2VRpR44rw)
And then you'll get the digital signature:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Ftalkimg.com%2Fimages%2F2023%2F11%2F15%2Fz5DE8.png&t=665&c=23ht2yq7XqpxEg)
As the others have stated, unless you know what you're doing... importing private keys can be a security risk, as you can potentially expose your private key. You are better off using a different desktop wallet like Electrum or Bitcoin
[1] or a hardware wallet etc.
[1] NOTE: you
don't have to download the full blockchain to be able to sign/verify messages with Bitcoin Core. So depending on your requirements, you might be able to use this if you're just wanting to stake an address that you don't intend to use for anything other than potential account recovery or proof of identity.
However, if you want to also use the staked address for transactions, then you will need to download the 260+gigs of blockchain!!