Bip39 Private Key Generator. The only reason All those letters are listed is to make it easier for our human brains to examine them and possibly memorize our recovery phrase. Passphrase values are saved within the /.tmp.tmp file about the MicroSD card. The values are encrypted with AES-256 (CTR method) https://totalbookmarking.com/story19028255/seed-function-in-r-facts-about-how-does-a-starter-generator-work-revealed