What is bip39 seed http://www.mediafire.com/file/uilrjfajg2ami24/pdf-14673-57158.pdf Checksum generation: A checksum is produced from this entropy using SHA-256 hashing, which allows confirm the mnemonic's integrity later on. For words that have only 3 letters, there is not any 4th letter. For instance Using the word “increase”, there aren't any more letters Later https://bookmarklinx.com/story20317438/bip39-cryptotag-not-known-details-about-bip39-generator-https-www-youtube-com-channel-ucupxfytj0fb78sq55hu6ocw