Bip39 Js. From this level forward the seed might be published on paper or spoken above phone which opened up new, physical means of backing up the seed (multiple paper copies in several spots, tough copies on metallic plates with additional security from fireplace/flood and so on.). gravity trophy suspect https://finance-department03692.wikijm.com/1101327/the_anatomy_of_the_bip39_phrase_entropy_text_and_protection