Bip39 encoding https://josueaqpi312.huicopper.com/leading-5-online-bip39-generators-for-easy-copyright-security Though it utilizes BIP32 process you could however import BIP39 seeds into Electrum wallet. Also other than BIp32 There may be BIP44 version which some wallet use for that generation of seeds. Push X to abort passphrase application and hold modifying the passphrase. Deciding... https://telegra.ph/Producing-Custom-Bitcoin-Addresses-A-Take-A-Look-At-BIP39-Strategies-06-28