Export account key

[coinbasis]

When you export account key from Mycelium, it shows a QR code with a very long text string ( 111 characters ). Why is this private key so long? The public key doesn't match with the unspent address in the account, so what is it exporting exactly?

[BitMaxz]

When you export account key from Mycelium, it shows a QR code with a very long text string ( 111 characters ). Why is this private key so long? The public key doesn't match with the unspent address in the account, so what is it exporting exactly?

It's a private extended key you can use this for recovering your wallet.

I stop using mycelium long time ago because until now they have no segwit addresses. So, I don't have much knowledge on how to export private key in mycelium.

Anyway, I found some methods that I think may help you to find the private keys and import to other wallet check this link extended key from mycelium

[NeuroticFish]

Why is this private key so long? The public key doesn't match with the unspent address in the account, so what is it exporting exactly?

It's not a private key. It's backup info.

Mycelium is a HD wallet, that means it automatically creates as many addresses it needs based on a seed. The seed usually have around 12 words, which is usually more than 111 characters. So the backup info is not too long.
And I repeat, to make it clear, it's not a private key, it's a backup (meaning enough info to re-create your HD wallet).

Quoted from Mycellium help pages:

The Backup gives the wallet a "starting point" (a secret) from there it is able to reproduce everything else it needs as it always does it the same way. This way you also only need to back it up once and not every time you add an address to your wallet.

[BitMaxz]

I repeat, to make it clear, it's not a private key, it's a backup (meaning enough info to re-create your HD wallet).

The 111 characters long is a extended private key (BIP32 Extended Key) check this sample below

Code:

xprv9s21ZrQH143K38naYWLuW252pDEkCAGydtdrfzvwuTfXosSQ8gEu6zqvAd3NQxRwumiKSxTCt6Qi1cNVka1EM9JEgPziAhsvspZHdgxW9YW

You need a 3rd party application to extract the seed phrase or private keys from the extended key.
You can check this tool as a reference http://bip32.org/

[bL4nkcode]

If you got it from Accounts tab -> 3 vertical dots from upper right  -> tap Export account keys(Public key), then it should be the extended public keys of you mycelium which starts with
"xpub" which is "public" and contains 111 characters the same as mine. But it might be good if you don't share it to anyone even its pub.
It composes all the used address of your HD wallet, which you can view it here https://www.blockchain.com/btc/xpub/<your xpub>

Code:

xpub6CUGRUonZSQ4TWtTMmzXdrXDtypWKiKrhko4egpiMZbpiaQL2jkwSB1icqYh2cfDfVxdx4df189oLKnC5fSwqPfgyP3hooxujYzAu3fDVmz

You can see it som discussion in reddit^[1]

[1] https://www.reddit.com/r/Bitcoin/comments/4nu0qr/what_is_an_xpub_address_and_how_is_it_different/


If you choose the Private one then its the one that starts "xprv" which explained above.

[bob123]

Why is this private key so long?

The extended private key (xpriv) is specified in BIP 32.
It is not a private key to actively spend your funds, it is used to generate private-/public- keys for you to receive/send BTC.
The xpriv is 111 bytes long, compared to 32 bytes for a 'standard' private key.

The public key doesn't match with the unspent address in the account, so what is it exporting exactly?

Could you please elaborate what exactly you are referring to ?
If you have exported the xpub (extended public key), you can generate 'all future' public keys (and therefore also addresses) of your wallet.
If you want to have a backup, you need to export the xpriv key.