Bip-39 https://zenwriting.net/keenanctdp/how-to-create-a-bip39-seed-a-step-by-step-guide Let us think it will be 10x quicker than the GFX card earlier mentioned so around two,4M hashes/s. An average attacker will possess a couple of these types of specialised gadgets. For words that have only three letters, there isn't a 4th letter. For instance with the word https://www.plurk.com/p/3hf2syltjx