I would like to create my own seed.
I picked out 11 words from the Bip39 list, but now I'm wondering how do I calculate the 12th word for my seed?
Is there a generator somewhere that can be used offline to calculate/display the 12th seed?
First off, congrats on wanting to generate your own seed phrase. I recently went deep down this rabbit hole cause I wanted a deeper understanding of how seed phrases work.
When you say that you "picked out 11 words", how did you pick them? Did you use a random word lottery? or flip a coin 128 times and convert that entropy into seed words?
There are a couple of online sources that I know of but you definitely DO NOT want to use any online service to calculate your checksum word. I am in the process of trying to figure out how to calculate the final checksum word in a completely offline and air-gapped way that is easy for noobs to do but it is more difficult than I would like it to be.
For experimentation and learning more about seed phrases and entropy, these tools are incredibly helpful.
Ian Coleman:
https://iancoleman.io/bip39/Bitcoiner Guide Seed Tool:
https://bitcoiner.guide/seed/SeedPicker:
https://seedpicker.net/calculator/last-word.htmlNOTE: There are all online so they are best suited for experimentation and learning. Do not use them to calculate a checksum word that you will use to hold real bitcoin unless you understand the risks involved and know EXACTLY how to run these programs completely offline.
Personally, I use a
SeedSigner and either flip a coin to generate the entropy for each seed word or I just use my
SeedSticks to randomly select 23 words and then calculate the final checksum word with my SeedSigner.
I actually wrote a series of articles on
4 steps to secure your seed phrase and securely generating your seed phrase is the first step.
Here are all 4 of the articles on how to secure your seed phrase if you're interested.
-
Generate your seed phrase-
Write your seed phrase-
store your seed phrase-
recover your wallet with your seed phrase
If I were you, I would do whatever possible to build a SeedSigner to calculate the final checksum word. It's currently the easiest way that I have found to calculate your final checksum word on an air-gapped device. SeedSigner is also my favorite hardware wallet device because of how easy it is to broadcast transactions while also keeping the device completely air-gapped.
I hope all of this helps you on your path to generating your own seed phrase as well as helping your friends and family to do the same.
Let me know if you have any questions or need some clarification.