10.4: Exporting Secrets from Bitcoin Core

We've spent three sections importing a secret into Bitcoin Core. We're now going to reverse course and see how to export a secret. (It's a lot easier!)

Reset Your Wallet

We're going to continue working in mainnet for this example, but you should use a Bitcoin Core-generated wallet, not the descriptor-based wallet we imported in the last section.

Unload your "seed" wallet from the last section or create a new "" wallet depending on what you've done to date with Bitcoin Core.

bitcoin-cli unloadwallet "seed"

| {
| }

bitcoin-cli listwallets

| [
|   ""
| ]

Understand What You Can Export

It would be ideal to export seeds or seed phrases, but Bitcoin Core doesn't currently support doing so.

That leaves you with two options:

Export a master private key, which can be used to recreate all descriptors.
Export individual descriptors.

The first option makes it easy to store just a tiny bit of information and restore everything from it, but you have to know what derivation paths your addresses are attached to (or else, you have to check addresses for every possible derivation path when you import).

The second option requires more data storage, but ensures that you have the precise data on the accounts (derivation paths) where you might have funds.

Understand Bitcoin Core Outputs

The listdescriptors RPC command is what you use to retrieve information about your keys and descriptors for export. You've seen it a number of times:

bitcoin-cli listdescriptors

| {
|   "wallet_name": "",
|   "descriptors": [
|     {
|       "desc": "pkh([3ce1d173/44h/0h/0h]xpub6BxVLeeQGSK4tVGLLZopaabNwFUZe223FfLCAa3PWNxpwqnCcZVRvDNH13fKh4Ea5w785U9a7u1LX5Tu9m9gpdi2i5PEE6aMNvXGi2LuKdV/0/*)#q8nl9w4h",
|       "timestamp": 1779999396,
|       "active": true,
|       "internal": false,
|       "range": [
|         0,
|         999
|       ],
|       "next": 0,
|       "next_index": 0
|     },
|     {
|       "desc": "pkh([3ce1d173/44h/0h/0h]xpub6BxVLeeQGSK4tVGLLZopaabNwFUZe223FfLCAa3PWNxpwqnCcZVRvDNH13fKh4Ea5w785U9a7u1LX5Tu9m9gpdi2i5PEE6aMNvXGi2LuKdV/1/*)#3nk7cm90",
|       "timestamp": 1779999396,
|       "active": true,
|       "internal": true,
|       "range": [
|         0,
|         999
|       ],
|       "next": 0,
|       "next_index": 0
|     },
|     {
|       "desc": "sh(wpkh([3ce1d173/49h/0h/0h]xpub6BopUUpLTpQDti8eEjdRKhp1bGcxHXJ9Mvdm23iSPSPh84ofH6icrDg8sH4kowsZEDcYynaHPqVS4mvrMvgHpi2sNKSBEG9s11SeR9yfvJ2/0/*))#32q0qkdf",
|       "timestamp": 1779999396,
|       "active": true,
|       "internal": false,
|       "range": [
|         0,
|         999
|       ],
|       "next": 0,
|       "next_index": 0
|     },
|
| ...
|   ]
| }

By default, each descriptor shown by listdescriptors contains the account public key for that descriptor. You'll note that they're the same for the external and internal descriptors for the address, but when you move on to a different derivation path, they're different.

So the public keys for the two 44h/0h/0h addresses are xpub6BxVLe... while the public key for the 49h/0h/0h address is xpub6BopUU.... You know that these addresses are account keys because the account derivation path is given before the key in the brackets.

Now, public keys aren't at all useful if you're trying to backup your secrets. Fortunately, listdescriptors will give you private keys if you add a true argument (which sets the private named argument to true).

bitcoin-cli -rpcwallet="" listdescriptors true

| {
|   "wallet_name": "",
|   "descriptors": [
|     {
|       "desc": "pkh(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/44h/0h/0h/0/*)#e0uydrgt",
|       "timestamp": 1779999396,
|       "active": true,
|       "internal": false,
|       "range": [
|         0,
|         999
|       ],
|       "next": 0,
|       "next_index": 0
|     },
|     {
|       "desc": "pkh(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/44h/0h/0h/1/*)#gme9skcn",
|       "timestamp": 1779999396,
|       "active": true,
|       "internal": true,
|       "range": [
|         0,
|         999
|       ],
|       "next": 0,
|       "next_index": 0
|     },
|     {
|       "desc": "sh(wpkh(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/49h/0h/0h/0/*))#pfqdkhdr",
|       "timestamp": 1779999396,
|       "active": true,
|       "internal": false,
|       "range": [
|         0,
|         999
|       ],
|       "next": 0,
|       "next_index": 0
|     },
|
| ...
| 
|   ]
| }

You'll note that the [bracketed] prefix is now gone. Instead, the entire derivation path appears after the key (which is now a private key). That means that you're now seeing the master private key, before any derivation occurs. As you'd expect, that master key is exactly the same for each of the accounts (derivation paths).

It's great that Bitcoin Core gives you access to the master private key.

It's not great that it shows the underived master key in each of its account descriptors, because that means that if any of them is compromised, they all are. (But we can use keytool to change what we store, which we'll do in the next section.)

Testing Derivation

If you're ever unsure of what Bitcoin Core (or any other Bitcoin program) is showing you, then you can always use keytool to test your understanding.

In this case, we think we understand that xprv9s21Zr... is a master private key and `xpub6BxVLe... is an account public key, derived from it for 44h/0h/0h. You can verify that by inputting the (purported) master key into keytool and verifying that the account public key for 44h/0h/0h is what you expect.

keytool --master-key xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4 --account-derivation-path "m/44h/0h/0h" account-pub-key-base58

| xpub6BxVLeeQGSK4tVGLLZopaabNwFUZe223FfLCAa3PWNxpwqnCcZVRvDNH13fKh4Ea5w785U9a7u1LX5Tu9m9gpdi2i5PEE6aMNvXGi2LuKdV

It is!

Store Your Data

You can now collect the information you'd need to restore this data. jq can be used to pull out the whole list of descriptors:

DESCS=$(bitcoin-cli listdescriptors true | jq -r '.descriptors[].desc')
DESC_ARRAY=($DESCS)

for ((i = 0; i < 8; i++)); do
  echo "$i: ${DESC_ARRAY[$i]}";
done

| 0: pkh(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/44h/0h/0h/0/*)#e0uydrgt
| 1: pkh(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/44h/0h/0h/1/*)#gme9skcn
| 2: sh(wpkh(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/49h/0h/0h/0/*))#pfqdkhdr
| 3: sh(wpkh(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/49h/0h/0h/1/*))#82ggd6xh
| 4: tr(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/86h/0h/0h/0/*)#q58cmp0l
| 5: tr(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/86h/0h/0h/1/*)#3qzex5l8
| 6: wpkh(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/84h/0h/0h/0/*)#u8jwrsql
| 7: wpkh(xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/84h/0h/0h/1/*)#dnh079s8

Since all of the descriptors include the master private key, you can retrieve it from any of them.

MP_KEY=$(echo ${DESC_ARRAY[0]} | awk -F"[()]" '{print $2}' | awk -F"/" '{print $1}')
echo $MP_KEY

| xprv9s21ZrQH143K4YGw3kaAmh3ezx1Xo4AanFmnX8TbaGghuNxXP9MDt2rPrLDyouX5kg9fiDJn7BELPnWRKwtVFn6aUBaNYJC9Mu6s39DnAo4/44h/0h/0h/0/*

Summary: Exporting Secrets from Bitcoin Core

Bitcoin Core doesn't currently allow you to export the seed. However, you can export either your master private key or your descriptors from the listdescriptors command

What's Next?

Conclude "Exploring the Ecosystem" with §10.5: Storing Secrets with Envelope.