Bip39 Algorithm. From this place forward the seed may very well be prepared on paper or spoken around telephone and this opened up new, physical means of backing up the seed (many paper copies in various spots, strong copies on metallic plates with excess defense from fireplace/flood and so forth.). https://kylerynbre.buscawiki.com/1111133/the_anatomy_of_a_bip39_phrase_entropy_text_and_stability