Bip39 Mnemonic Brute Force. From this position ahead the seed could be penned on paper or spoken around telephone and this opened up new, Actual physical ways of backing up the seed (multiple paper copies in several spots, long lasting copies on metallic plates with extra protection from hearth/flood and https://miloukynb.wikipublicity.com/5951423/the_anatomy_of_the_bip39_phrase_entropy_terms_and_safety