Creating Ethereum, Bitcoin and other accounts is complex and fraught with potential for loss of funds.
A BIP-39 seed recovery phrase helps, but a single lapse in security dooms the account (and all derived accounts, in fact). If someone finds your recovery phrase (or you lose it), the accounts derived from that seed are /gone/.
The SLIP-39 standard allows you to split the seed between 1, 2, or more groups of several mnemonic recovery phrases. This is better, but creating such accounts is difficult; presently, only the Trezor supports these, and they can only be created "manually". Writing down 5 or more sets of 20 words is difficult, error-prone and time consuming.
Your keys, your Bitcoin. Not your keys, not your Bitcoin.
---Andreas Antonopoulos
The [python-slip39] project (and the [SLIP-39 macOS/win32 App]) exists to assist in the safe creation, backup and documentation of [Hierarchical Deterministic (HD) Wallet] seeds and derived accounts, with various SLIP-39 sharing parameters. It generates the new random wallet seed, and generates the expected standard Ethereum account(s) (at [derivation path] m/44'/60'/0'/0/0 by default) and Bitcoin accounts (at Bech32 derivation path m/84'/0'/0'/0/0 by default), with wallet address and QR code (compatible with Trezor and Ledger derivations). It produces the required SLIP-39 phrases, and outputs a single PDF containing all the required printable cards to document the seed (and the specified derived accounts).
On an secure (ideally air-gapped) computer, new seeds can /safely/ be generated (without trusting this program) and the PDF saved to a USB drive for printing (or directly printed without the file being saved to disk.). Presently, `slip39' can output example ETH, BTC, LTC, DOGE, BNB, and XRP addresses derived from the seed, to /illustrate/ what accounts are associated with the backed-up seed. Recovery of the seed to a [Trezor Safe 3] is simple, by entering the mnemonics right on the device.
We also support the backup of existing insecure and unreliable 12- or 24-word BIP-39 Mnemonic Phrases as SLIP-39 Mnemonic cards, for existing BIP-39 hardware wallets like the [Ledger Nano], etc.! Recover from your existing BIP-39 Seed Phrase Mnemonic, select "Using BIP-39" (and enter your BIP-39 passphrase), and generate a set of SLIP-39 Mnemonic cards. Later, use the SLIP-39 App to recover from your SLIP-39 Mnemonic cards, click "Using BIP-39" to get your BIP-39 Mnemonic back, and use it (and your passphrase) to recover your accounts to your Ledger (or other) hardware wallet.
Output of BIP-38 or JSON encrypted Paper Wallets is also supported, for import into standard software cryptocurrency wallets.