BIP39 isn't perfect, but being able to relatively independently of all other information recover someone's wallet (next of kin, etc.) from some words is very nice. This system complicates things a lot -- a grid of custom construction which will possibly not be stored, ambiguity in specifying the graphical pattern, etc.
Do I understand this correctly that you need to safely store your random grid since only the pattern is in your head? Losing the grid would then essentially mean you can't access your keys anymore even though someone else also can't. But maybe I overlooked something. Will take another look tomorrow.
However, I want to mention the technique of making up a story to remember the seed words. I found this to be fairly easy so I am not sure how this grid can be more useful than that.
But still a very cool and interesting idea! Thanks for sharing. (You even made me create a HN account to post my first comment)
The tutorial is quite long, so it's possible I missed this information somewhere. But what I would like to see is a breakdown like "If you have X bits of entropy in your seed phrase, a border wallet puts Y bits of that into the grid and Z bits of that into your memorized pattern." This would make it clear how much security you're gaining over just writing down the seed phrase (Z bits worth).
It's hard for me to meaningfully distinguish the advantage of this v. e.g
1) "half" is six words you memorize
2) "other half" is a long annoying non-memorizable string that must be written down?
Am I missing something?
This falls into the general category of brain wallets.
https://en.bitcoin.it/wiki/Brainwallet
I once generated a Bitcoin private key with a SHA-256 hash of a pop song lyric. Within 3-days the roughly $100 I sent to that wallet, as a test, was drained.
Entropy matters.