Vault Key Backup and Restore

CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. key material is shared across the CORE and the participants while its management data is stored in the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. DB. The backup of this data is divided into steps done during setup and steps needed in an ongoing basis. The backup data is used for recovery.

CASP Key Backup and Restore

The numbers in the figure correspond to the respective steps in the next section.

Backup

Setup Tasks for Backup

During setup, perform these tasks:

  1. Create RSA keys that will be used to encrypt and decrypt the backup of CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. vault key.

    The vault key backup is applied to recover CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. vault key from a loss of the entire system. See Prepare Vault Key Recovery.

  2. Setup the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. vault key backup encryption.

    The public RSA keys are installed on CORE. See Setup CORE.

  3. Create a CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. quorumClosedOne or more groups, comprised of participants with redundancy.

    Your quorumClosedOne or more groups, comprised of participants groups should have more participants than the required minimum number for approval. This setup allows replacing a participantClosedA member of any of the quorum groups., which may be necessary if someone loses their phone or leaves the company. For example, your group has 3 participants required for approvals, and it has 4 participants. A participantClosedA member of any of the quorum groups. loses his phone, and the remaining 3 can reactivate the participantClosedA member of any of the quorum groups. on a new phone.

    Consider creating a couple of bots that are used as participants. These bots can be safely stored and only used when needed to meet the minimum quorumClosedOne or more groups, comprised of participants for approval.

  4. Setup the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. database backup.

    Use the methods described by each database vendor for backup of your CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. DB:

    It can be helpful to save a copy of your casp.conf configuration file.

Ongoing Backup Tasks

The following are ongoing backup tasks to execute periodically:

  1. Backup the vault key.

    You should backup the vault key immediately upon creation of the vault.

    Note:

    • For BIP32 vaults, it backs up the first key that was derived normally on the derivation chain. For example:

      • For the chain m/0'/1'/2/3/4 - it backs up only the 2 key.

      • For the chain m/1/2/3/4 - it backs up only the 1 key.

    • For BIP44 vaults, it backs up only the account key.

    2. Use the APIs found in the CASP API descriptions:

    To retrieve the backup data, use one of the following API requests:

    • For a deterministicClosedCalculation that each time results in the same value (non-hierarchical) vault use:

      https://<casp-server>/api/v1.0/mng/vaults/{id}/backup

      See Get vault backup data.

    • For BIP32 use:

      https://<casp-server>/api/v1.0/mng/vaults/{vaultId}/backup/{publicKey}

      See Get backup data for public key.

    • For BIP44 use:

      https://<casp-server>/api/v1.0/mng/vaults/{id}/coins/{coin-number}/accounts/{account-number}/backup

      Replace {coin-number} with the number for the coin type that you are using. You can see a list here.
      Replace {account-number} with your account number. You need to call this command once for each account number.

      Note
      This is the backup of the account root key, not the actual key that holds the currency. All other account addresses can be derived from this key.

      See Get backup for account.

    The returned JSON includes encrypted vault key and metadata required for its restoration. Save the returned JSON to a file for use in the verify/restore process.

    Warning
    Segregate a backup file from the keys required to decrypt the file's material.

  2. Backup the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. database.

    Use the methods described by each database vendor for periodic backups of your CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. DB:

  3. Backup the CORE.

    4. Backup CORE periodically. Use the CORE procedures, which can be found in the CORE User Guide.

Recovery Scenarios

The following sections present different recovery scenarios and what is required to restore functionality.

CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. provides the Status API that returns the health of the components. You can run this command to help determine which component has an issue. In addition, you can test the components with the commands in Testing the CASP System.

Lost Phone, Damaged Bot, or Employee Replacement

There are several similar situations that have similar recovery procedures:

  1. Lost phone - one of the participants in your quorumClosedOne or more groups, comprised of participants group loses their phone. This participantClosedA member of any of the quorum groups. gets a new phone and needs to be reactivated by the remaining participants.
  2. Employee replacement or a damaged bot - an employee who is a participantClosedA member of any of the quorum groups. in your quorumClosedOne or more groups, comprised of participants group either switches positions or leaves the company. Alternatively, you have a bot that gets damaged. This participantClosedA member of any of the quorum groups. now needs to be replaced in the quorumClosedOne or more groups, comprised of participants.

The CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. vault implementation has built-in support for these scenarios. For a lost phone, the participantClosedA member of any of the quorum groups. can just be reactivated. To replace a participantClosedA member of any of the quorum groups., deactivate the current participantClosedA member of any of the quorum groups. from the relevant vault and then add the replacement participantClosedA member of any of the quorum groups. to the vault.

These actions are part of the regular operations supported by CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. vaults and do not require any specific disaster recovery protocol. For details about adding participants to an existing vault, deactivating participants, and reactivating participants, refer to the Participant Flows.

CORE Loss

Run the Status API to determine if there is a problem with the CORE. This API returns the health of the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. components.

If a CORE server or cluster is lost or destroyed, you can bring up a new set of servers and then restore from your backups. See the CORE Restore Procedure.

After restoring, rerun the Status API to determine all components are healthy.

CASP Server Loss

If the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. server (i.e., the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. Orchestrator) holding your CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. vaults is lost, you can install new CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. server. If you saved the casp.conf configuration file, copy it to the new server. If not, recreate the casp.conf file using the parameters for the existing CORE and database.

After restoring, rerun the Status API to determine all components are healthy.

CASP Database Loss

Run the Status API to determine if there is a problem with the database. This API returns the health of the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. components.

If the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. database is lost, you can use the methods described by each database vendor to restore the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. backup:

After restoring, rerun the Status API to determine all components are healthy.

Total System Loss

In case of a total loss of the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. system, including CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions., CORE, and the database, the private keys in vault can still be recovered if you have the cold backup key and the vault backup.

The previous methods are for restoring CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. components for recovery of the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. system itself. However, there are cases where it is required to restore the actual vaults outside of at the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. system, such as in a standalone compatible wallet.

Other use cases include:

  1. An exchange system where the customerClosedThe entity that initially holds the crypto asset and requests storage in the crypto asset vault. wants to be able to recover funds even if the exchange service ceases to operate. For this case, it can store the backup data in a different location and the backup key in a safe location outside of the exchange system.
  2. Moving from CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. to a different vault system.

Using this approach requires the following steps:

  1. Set up the backup keys during CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. installation (see Prepare Vault Key Recovery).
  2. Get the backup data per generated vault and sub-account.
  3. Verify the backup information using the verify option of the CASP Restore Utility. This option allows you to verify backup data integrity without decrypting the vault key.
  4. Use the backup data along with the private key to retrieve the original seed/key using the restore option of the CASP Restore Utility.

CASP Restore Utility

Unbound CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. includes casp_restore utility that enables verification of the encrypted vault key backup and reconstruction of the vault key. This utility is installed by the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. RPMClosedFile format for software package distributed by RPM Package Manager (and is also available as a separate download).

The casp_restore runs on these platforms:

  • RHEL/CentOS 7.2 and later
  • Ubuntu 16.04

It uses the following parameters:

The utility is called with the following command line:

casp_restore [options]

It has these options:

Note
This utility is backward compatible with backups created using a single RSA key before version 2.0.2112. To restore such backups, omit the -rsa2 parameter and its password

Master Key Extractor

Note
This script only works for Bitcoin. For other wallets, please contact Unbound Support.

A Python script, called Master Key Extractor, is provided along with the CASPClosedUnbound’s Crypto Asset Security Platform (“CASP”) provides the advanced technology and the architecture to secure crypto asset transactions. Restore utility. Master Key Extractor creates a BIP32 master key from a .pem file. The .pem file is the output of the CASP Restore Utility.

The script is called with the following command line:

masterkey_extractor.py [options]

The script has these options:

The output of the script is a master key (in xprv format), like so:

abcd1234ABCD5678Z1CeAh2pKFwY8JLjVQDXUoFQwMbAuUgYCtFnyA9jwFixgUJRRBVsVQ\
AGK4VcXBHjBsWhqGhiuLQXj9habcd1234ABCD5678

The string includes the private key and other derivation information that was provided to the script. It can be used by other wallets to derive the keys that have actual funds associated with them.

Restore Examples

Restore a Deterministic (non-BIP) Vault

The following steps show an example of restoring a deterministicClosedCalculation that each time results in the same value vault.

  1. For this example, we use these parameters:
  2. Get the backup data.

    3. curl --request GET \
    --url http://192.168.0.149/casp/api/v1.0/mng/vaults/381ab347-0e18-4bdf-8a7f-7f02332e655f/backup \
    --header 'authorization: Bearer b3JpOjJkOTMyNGYzLTM0MjItNDgwNC1hYTkyLWY5ZThlYWExNmRmYw=='

    Response:

    {
    "vaultID": "381ab347-0e18-4bdf-8a7f-7f02332e655f",
    "backupData": "ZWNiYWNrMDEAgALKAQAQ"
    }

    Note
    The backupData field has been truncated for example purposes.

  3. Save the contents (without the quotes) of the received backupData field to a file, called backupData.txt.
  4. Get the public key.

    5. curl --request GET \
    --url http://192.168.0.149/casp/api/v1.0/mng/vaults/381ab347-0e18-4bdf-8a7f-7f02332e655f/publickey \
    --header 'authorization: Bearer b3JpOjJkOTMyNGYzLTM0MjItNDgwNC1hYTkyLWY5ZThlYWExNmRmYw=='

    Response:

    {
    "publicKey": "3056301006072A8648CE3D020106052B8104000A03420004D40671DD6DB05B96721BF8\
    54EF56E7EDD9FC10B4CED0090F365740513CFDE7A8691C6CA4ACBE307B0BCFBFF6F56397\
    D2C015AD6C437CB2482DFA019DF23657D6"
    }

  5. Save the contents (without the quotes) of the received publicKey field to a file, called publicKey.txt.
  6. Run the CASP Restore Utility.

    7. /opt/casp/bin/casp_restore -op restore -alg ecdsa -in backupData.txt -rsa casp_backup_private.pem -public-key publicKey.txt -out ec-key

  7. Convert the received key into plain text.

    8. openssl ec -in ec-key -outform PEM -out restored.plain.pem

  8. Run the Master Key Extractor.

    9. python /tmp/masterkey_extractor.py -p restored.plain.pem --testnet

You now have the master key (in WIF format), which is a string that includes the private key that was provided to the script. It can be used by other wallets that have actual funds associated with them.

To restore your wallet, use the master key in Electrum:

  1. In Electrum, select File > New/Restore.
  2. Give the wallet a name and then click Next.
  3. Select Import Bitcoin addresses or private keys, and then click Next.
  4. Enter the master key, and then click Next.

A wallet is created using the master key.

Restore an HD (BIP44) Vault

The following steps show an example of restoring an HDClosedHierarchical Deterministic - a type of deterministic Bitcoin wallet derived from a known seed, that allows for the creation of child keys from the parent key. Because the child key is generated from a known seed there is a relationship between the child and parent keys that is invisible to anyone without that seed. vault.

  1. For this example, we use these parameters:
  2. Get the backup data.

    3. curl --request GET \
    --url http://192.168.0.166/casp/api/v1.0/mng/vaults/db15bb8d-baec-4ceb-858c-7ae967261933/coins/1/accounts/0/backup

    Response:

    {
    "backupData": "ZWNiYWNrMDEAgALKAQAIAAACAo+aT5hBI2WZiNvmLR8dr4pe/MJ",
    "bipLevel": 3,
    "cpar": "772FB73BF97DF1E7E1A8BA6BC3F9656D8A633DF9873C0C2DBAC2003C65A6A652",
    "parentFingerprint": "2039A9A5",
    "childNumber": 0,
    "publicKey": "3056301006072A8648CE3D020106052B8104000A03420004E7A1172F667C3923C6C40AC\
    A03E392457820B0F7CE144007919F4363BCF978EAE51188C10287A8E6FE211CFBB7166B09\
    47AAB56324635AC60C0009296F28EC64"
    }

    Note

    The backupData field has been truncated for example purposes.

  3. Save the contents (without the quotes) of the received backupData field to a file, called backupData.txt.
  4. Save the contents (without the quotes) of the received publicKey field to a file, called publicKey.txt.
  5. Run the CASP Restore Utility.

    6. /opt/casp/bin/casp_restore -op restore -alg ecdsa -in backupData.txt -rsa casp_backup_private.pem -public-key publicKey.txt -out ec-key

  6. Convert the received key into plain text.

    7. openssl ec -in ec-key -outform PEM -out restored.plain.pem

  7. Run the Master Key Extractor. The parameters are from the response of the backup curl command.

    8. python /tmp/masterkey_extractor.py -p restored.plain.pem \
    -l 3 \
    -c 772FB73BF97DF1E7E1A8BA6BC3F9656D8A633DF9873C0C2DBAC2003C65A6A652 \
    -n 0 \
    -f 2039A9A5 \
    --testnet

You now have the master key (in xprv/tprv format), which is a string that includes the private key and other derivation information that was provided to the script. It can be used by other wallets to derive the keys that have actual funds associated with them.

To restore your wallet, use the master key in Electrum:

  1. In Electrum, select File > New/Restore.
  2. Give the wallet a name and then click Next.
  3. Select Standard wallet, and then click Next.
  4. Select Use a master key, and then click Next.
  5. Enter the master key, and then click Next.

A BIP wallet is created using the master key.