[[appdx_bx]] [appendix] == Bitcoin Explorer (bx) Commands ((("Bitcoin Explorer (bx) commands", id="BX18_1", range="startofrange")))Bitcoin Explorer (bx) is a command-line tool that offers a variety of commands for key management and transaction construction. It is part of the libbitcoin bitcoin library. ---- Usage: bx COMMAND [--help] Info: The bx commands are: address-decode address-embed address-encode address-validate base16-decode base16-encode base58-decode base58-encode base58check-decode base58check-encode base64-decode base64-encode bitcoin160 bitcoin256 btc-to-satoshi ec-add ec-add-secrets ec-multiply ec-multiply-secrets ec-new ec-to-address ec-to-public ec-to-wif fetch-balance fetch-header fetch-height fetch-history fetch-stealth fetch-tx fetch-tx-index hd-new hd-private hd-public hd-to-address hd-to-ec hd-to-public hd-to-wif help input-set input-sign input-validate message-sign message-validate mnemonic-decode mnemonic-encode ripemd160 satoshi-to-btc script-decode script-encode script-to-address seed send-tx send-tx-node send-tx-p2p settings sha160 sha256 sha512 stealth-decode stealth-encode stealth-public stealth-secret stealth-shared tx-decode tx-encode uri-decode uri-encode validate-tx watch-address wif-to-ec wif-to-public wrap-decode wrap-encode ---- For more information, see the https://github.com/libbitcoin/libbitcoin-explorer[Bitcoin Explorer homepage] and https://github.com/libbitcoin/libbitcoin-explorer/wiki[Bitcoin Explorer user documentation]. === Examples of bx Command Use Let's look at some examples of using Bitcoin Explorer commands to experiment with keys and addresses. Generate a random "seed" value using the +seed+ command, which uses the operating system's random number generator. Pass the seed to the +ec-new+ command to generate a new private key. We save the standard output into the file _private_key_: ---- $ bx seed | bx ec-new > private_key $ cat private_key 73096ed11ab9f1db6135857958ece7d73ea7c30862145bcc4bbc7649075de474 ---- Now, generate the public key from that private key using the +ec-to-public+ command. We pass the _private_key_ file into the standard input and save the standard output of the command into a new file _public_key_: ---- $ bx ec-to-public < private_key > public_key $ cat public_key 02fca46a6006a62dfdd2dbb2149359d0d97a04f430f12a7626dd409256c12be500 ---- We can reformat the +public_key+ as an address using the +ec-to-address+ command. We pass the _public_key_ into standard input: ---- $ bx ec-to-address < public_key 17re1S4Q8ZHyCP8Kw7xQad1Lr6XUzWUnkG ---- Keys generated in this manner produce a type-0 nondeterministic wallet. That means that each key is generated from an independent seed. Bitcoin Explorer commands can also generate keys deterministically, in accordance with BIP32. In this case, a "master" key is created from a seed and then extended deterministically to produce a tree of subkeys, resulting in a type-2 deterministic wallet. First, we use the +seed+ and +hd-new+ commands to generate a master key that will be used as the basis to derive a hierarchy of keys: ---- $ bx seed > seed $ cat seed eb68ee9f3df6bd4441a9feadec179ff1 $ bx hd-new < seed > master $ cat master xprv9s21ZrQH143K2BEhMYpNQoUvAgiEjArAVaZaCTgsaGe6LsAnwubeiTcDzd23mAoyizm9cApe51gNfLMkBqkYoWWMCRwzfuJk8RwF1SVEpAQ ---- We now use the +hd-private+ command to generate a hardened "account" key and a sequence of two private keys within the account: ---- $ bx hd-private --hard < master > account $ cat account xprv9vkDLt81dTKjwHB8fsVB5QK8cGnzveChzSrtCfvu3aMWvQaThp59ueufuyQ8Qi3qpjk4aKsbmbfxwcgS8PYbgoR2NWHeLyvg4DhoEE68A1n $ bx hd-private --index 0 < account xprv9xHfb6w1vX9xgZyPNXVgAhPxSsEkeRcPHEUV5iJcVEsuUEACvR3NRY3fpGhcnBiDbvG4LgndirDsia1e9F3DWPkX7Tp1V1u97HKG1FJwUpU $ bx hd-private --index 1 < account xprv9xHfb6w1vX9xjc8XbN4GN86jzNAZ6xHEqYxzbLB4fzHFd6VqCLPGRZFsdjsuMVERadbgDbziCRJru9n6tzEWrASVpEdrZrFidt1RDfn4yA3 ---- Next, we use the +hd-public+ command to generate the corresponding sequence of two public keys: ---- $ bx hd-public --index 0 < account xpub6BH1zcTuktiFu43rUZ2gXqLgzu5F3tLEeTQ5t6iE3aQtM2VMTxMcyLN9fYHiGhGpQe9QQYmqL2eYPFJ3vezHz5wzaSW4FiGrseNDR4LKqTy $ bx hd-public --index 1 < account xpub6BH1zcTuktiFx6CzhPbGjG3UYQ13WR16CmtbPiagEKpEVtpyjshWyMaMV1cn7nUPUkgQHPVXJVqsrA8xWbGQDhohEcDFTEYMvYzwRD7Juf8 ---- The public keys can also be derived from their corresponding private keys using the +hd-to-public+ command: ---- $ bx hd-private --index 0 < account | bx hd-to-public xpub6BH1zcTuktiFu43rUZ2gXqLgzu5F3tLEeTQ5t6iE3aQtM2VMTxMcyLN9fYHiGhGpQe9QQYmqL2eYPFJ3vezHz5wzaSW4FiGrseNDR4LKqTy $ bx hd-private --index 1 < account | bx hd-to-public xpub6BH1zcTuktiFx6CzhPbGjG3UYQ13WR16CmtbPiagEKpEVtpyjshWyMaMV1cn7nUPUkgQHPVXJVqsrA8xWbGQDhohEcDFTEYMvYzwRD7Juf8 ---- We can generate a practically limitless number of keys in a deterministic chain, all derived from a single seed. This technique is used in many wallet applications to generate keys that can be backed up and restored with a single seed value. This is easier than having to back up the wallet with all its randomly generated keys every time a new key is created. The seed can be encoded using the +mnemonic-encode+ command: ---- $ bx hd-mnemonic < seed > words adore repeat vision worst especially veil inch woman cast recall dwell appreciate ---- The seed can then be decoded using the +mnemonic-decode+ command: ---- $ bx mnemonic-decode < words eb68ee9f3df6bd4441a9feadec179ff1 ---- Mnemonic encoding can make the seed easier to record and even remember.(((range="endofrange", startref="BX18_1")))