Bip39 Passphrase Empty For None ) Or for really higher stability, you might "roll your own personal" seed phrase with dice or even a calculator as offline methods. This technique is used in all Digital slot equipment in casinos. Their pseudo-random quantity generators generate about 500 figures for every second, https://bookmarkdistrict.com/story18290898/list-of-bip39-wallets-not-known-facts-about-bip39-phrase