How to Encrypt a Wallet Seed

There are two standard ways of encrypting a wallet seed. The Key Encryption method allows you to encrypt an existing wallet seed. The Mnemonic method requires you to accept a seed derived from an initial seed (which is not recoverable).

Using Key Encryption

Create a new HD key.

$ bx seed -b 256 | bx hd-new

c82425d18a88ea6c5a92d06bc4ee26bfaf1b8782e7c0537544ae6dd40bb5083b
xprv9s21ZrQH143K4EdfsuwWHdxaGgcwGkTB1f71fbzJNfJma1Xga5XE3LqYxXKkwJJLevsp16iDRyk35MwvmKEEyyqLkHQVziTNs6VtPr1xGM8

Encrypt the seed (using a stronger passphrase).

$ bx ec-to-ek "my passphrase" c82425d18a88ea6c5a92d06bc4ee26bfaf1b8782e7c0537544ae6dd40bb5083b

6PYVupXn6GTGVxpdVgamwbnTzh8hNAswxDeAhUc5ufTCRu8KZgjoSQEqSN

Verify your ability to recover the HD key.

$ bx ek-to-ec "my passphrase" 6PYVj8maQYA95fREvtpgBMFtbi7U2T1B85zyjmEPqC7MknXowoV7yKzHXL | bx hd-new

xprv9s21ZrQH143K2uNeWu3crjqwic1ocvMMwRSypQyMDTk4yQedZv8zkBVUeq2gztk2HQCAvqNLhUfcHhbD1RGFQ1TTqDSWfTLW4qkxsPMdjNG

Using Mnemonics

The passphrase is optional but if not used the mnemonic is not encrypted and therefore must be kept secret. See also Remembering a Seed.

Create a new mnemonic.

$ bx seed -b 128 | bx mnemonic-new

betray senior exhibit slot apart affair welcome dog hockey razor cart side

Generate a new HD wallet from the seed (using a stronger passphrase).

$ bx mnemonic-to-seed -p "my passphrase" betray senior exhibit slot apart affair welcome dog hockey razor cart side | bx hd-new

xprv9s21ZrQH143K38Jah6HduU5yGFkyDqtVDn24E1vjSMZ9vqdtCnUYn1v7pPedGoNvDFzjUG77VuYjWptQLsbCzqMy3AYXaWWFo7cbAvBxPqa

Verify your ability to recover the HD key.

$ bx mnemonic-to-seed -p "my passphrase" betray senior exhibit slot apart affair welcome dog hockey razor cart side | bx hd-new

xprv9s21ZrQH143K38Jah6HduU5yGFkyDqtVDn24E1vjSMZ9vqdtCnUYn1v7pPedGoNvDFzjUG77VuYjWptQLsbCzqMy3AYXaWWFo7cbAvBxPqa