2/ The full 720x480 image is run through SHA-256 to generate your 24-word mnemonic. The full image is never displayed (only the center crop). The image is never saved.
@SeedSigner is stateless so everything goes away when you turn it off.
3/ Next you can do the manual QR code transcription using the dedicated UI and our grid template.
This one took me 13 minutes. You can be way sloppier and go much faster than this. QR codes are amazingly resilient to errors.
4/ I print the template on 110# cardstock paper to give it some stiffness. Then cut and prep it for the thermal laminator.
5/ Thermal laminators are f'n cool.
6/ But your real backup should be metal. Hello, @blockmit_com!
Badass self-sovereignty group photo right here!
7/ Give it a try. Scan this with your phone. The stream of numbers you get back are the four-digit indices of the BIP-39 wordlist for each word, in order.
1364 pride
0098 arrange
0811 grace
etc
8/ Biggest criticism: But now it's too easy for someone to snap a pic of your seed QR!
* What, are you doing this in a coffee shop?! Um, private spaces only.
Why bother with this? The external fan is so freakin' quiet that it (plus a Noctua fan for the psu) makes an S9 totally viable as a space heater in any room.
Default S9 fans (set to ~1100W) are a bit worse than a loud bathroom exhaust. Not horrible, but not quiet.
Here's the fan. It isn't completely silent but you could easily sleep next to it.
And because it wasn't pulling enough cfms, I ditched the speed controller entirely so it's running at max speed (which isn't so max).
* v0.5.x has been out since April. It's f'n awesome and still gaining more features.
* But the Raspi Zero is near-impossible to find.
* We must port to alternate hardware.
* Begin MicroPython R&D hell.
Strategy:
Focus on easily-sourced microcontrollers (MCUs) instead of Pi-like single-board computers (SBCs).
The Pi Zero was an amazing cheat to get @SeedSigner off the ground quickly, but an MCU always made more sense (e.g. waiting 45s for linux to load is ridiculous).
The most popular MCU afaik is the STM32 line. But they're in supply chain hell. "See you in 2023" is not an option.
ALMOST through the hardest parts of @SeedSigner's PSBT review screens.
BIG breakthrough: realizing we can confirm change addrs much more easily than previously thought!
We can instantly provide assurances that single sig change addrs are legit. Multisig requires a 2nd step.
"35c5d905: change #0" means:
* For the seed that we selected to sign this psbt (ID'ed by its fingerprint)...
* The addr from the psbt was confirmed to match the seed's first (#0) change addr.
This is undeniably my seed's correct change addr. My change is not being stolen.
And, yes, probably the "confirmed address for seed" label could be improved. So f'n hard to convey complex concepts in limited real estate!
Experimenting with this @SeedSigner PSBT warning screen.
If your coordinator software gives you an evil PSBT that steals your change output, this would call that out.
But legit txs can obv be a full spend, too.
So too scary or confusing for noobs? Better wording ideas?
Obv a noob could misconstrue "input value" with "OMG is it stealing my WHOLE WALLET?!!"
But I think noobs are unlikely to ever construct a tx that spends exactly a whole utxo (and so wouldn't see this warning) unless they're actually sweeping their whole wallet.
The other possibility is that they're trying to sign with the wrong key.
(though me may be able to prevent this from happening, too)