Bip39 Ian Coleman. Entropy values have to be sourced from a powerful source of randomness. This means flipping a fair coin, rolling a fair dice, noise measurements etc. Do NOT use phrases from publications, lyrics from songs, your birthday or steet address, keyboard mashing, or something you think is random, https://morningdirectory.com/listings545814/bip39-list-https-linktr-ee-bip39-5-simple-statements-about-bip39-compatible-wallet-explained