Bip39 numbers https://www.plurk.com/p/3hf2syltjx While it uses BIP32 strategy you'll be able to nevertheless import BIP39 seeds into Electrum wallet. Also aside from BIp32 there is BIP44 Edition which some wallet use for that technology of seeds. Due to the cryptographic structure of BIP-39, a weak passphrase won't reduce the protection https://socialtechnet.com/story6183975/bip-39-how-many-words-the-5-second-trick-for-bip39-mnemonic-code-converter-tool-https-www-youtube-com-channel-ucupxfytj0fb78sq55hu6ocw