Specter DIY hardware wallet

[nortwood]

I searched but couldn't find any reference to this project, but it seems promising. It's a nice DIY air gapped wallet with QR reader and touchscreen for $120-$140. It also looks like it can be used without the QR scanner via usb in which case it's $75:
https://github.com/cryptoadvance/specter-diy
https://www.youtube.com/watch?v=eF4cgK_L6T4

I got a stm32 board today and had the code uploaded running in less than 5min. No arduino IDE, no microPython. Just dragged and dropped the .bin file and that was that. I've only ever had a ledgers so it feels like a real treat.

Are others familiar with the code?


disclaimer:

This project is not very mature yet, USE AT YOUR OWN RISK. Some error messages might be not very user friendly, but they help to debug and fix issues. If you see an unexpected error message please open an issue and we will try to fix it. Sometimes reboot helps.

This wallet is a FUNCTIONAL PROTOTYPE. This means we use it to experiment with user interface, communication methods and new interesting features (like miniscript, CoinJoin and Lightning).

[Pmalek]

I don't think this wallet will appeal to many users considering it's a do it yourself type of project. The buyer would need to connect all the components so it would be something only tech geeks and those who like to create things with their own two hands would want to buy. With a price tag of up to $140, it's not cheap either. There are more affordable hardware wallets that you can just plug in and they work. 

This might be something Ratimov and FatFork could take a look at to include in their lists of hardware wallets.

[dkbit98]

I was following Specter DIY wallet for some time and I like the idea of people making their own wallets from available components, but this is not for everyone and not for general public.
I think there was recently some bug found in their code reported as false trojan alert, and I don't like the fact that Specter doesn't have any secure element.
Good thing is that many software wallets including Electrum are supported as well as multisig option with other hardware wallets,
but cost of making this device is too high for me to justify making it for everyday use, but as a hobby project I think it is cool.
Here is Specter website: https://specter.solutions/

[nortwood]

I thought it would be more difficult than it actually is. I'm not using the dev kit with the smart card reader and battery built-in, or the diy method shown on youtube. I'm just using a 3d printed case from thingiverse (thank you Seed Signer) to house everything rather than glue it. So the only thing to put together is to attach 4 jumper wires from the camera to the device, and slap the case together. 

STM32 module (touch screen/microprocessor) - $75
QR camera - $45 (probably could use a cheaper $6 ov246 mini arduino module)
3d printed case - free (https://www.thingiverse.com/thing:4680700)

The STM32 module has a sd card reader, which can be encrypted as a secure element. Or you could elect to go with a $13 smart card reader from Amazon, which is what I'm doing.

[dkbit98]

...

Yeah it's not complicated to make your own wallet following instructions, and when I was calculating price it was a bit more expensive, but problem is that there is big shortage of chips and electronics now in market so prices are going up.
3d printing is only free if you have 3d printer yourself, if not you still need to pay someone to print the case for you.
For same price you can purchase ready Coldcard open source wallet with secure element, or Bitbox that is also open source, not to mention Ledger and Trezor.

[hugeblack]

This HW contains a lot of features that beginners want and developers do not look for, but with that it is mainly for developers and not for beginners because mostly beginners want something easy, simple and focused on the interface.
Generally, if these wallets become more popular and there is an option to order the parts you want and assemble them either yourself or have them assembled for you, the price adjustment will be appropriate.

[nortwood]

I agree that without the printer perhaps it's not as intriguing. I have no idea what Seed Signer would ask for a printed case. But I couldn't imagine much.

Coldcard was definitely the other option I was looking at. To me the STM32 board without the camera would basically serve the same purpose. I could be underestimating the Coldcard. Like I said, I've only used ledgers so for me anything to get away from those buttons is a step forward, and I couldn't justify buying multiple more expensive ones. I also really like the approach to entropy on the Specter:

https://www.youtube.com/watch?v=76p0ADx9gXw

Btw, I'm in no way affiliated with this project, no do I know anyone involved. I just stumbled on it this week and found it stupid simple to get going. If you watch the videos on youtube he talks about it's limitations and advantages fairly candidly. Though I value the criticism of others more capable of understanding security trade off. 

an option to order the parts you want and assemble them either yourself

I didn't order anything from them. I also didn't check alibaba/aliexpresss. These were purchases this week from random US electronic suppliers.

I believe Specter developed and sells a shield for the STM32 board that has a battery and smart card reader built in for a sleek form factor. Everything else is open source. 

[dkbit98]

To me the STM32 board without the camera would basically serve the same purpose.

I purchased cheap ESP32 from China that is similar with STM32 and it cost around $10 or $20, there is even one with camera that is a bit more expensive.

I could be underestimating the Coldcard. Like I said, I've only used ledgers so for me anything to get away from those buttons is a step forward, and I couldn't justify buying multiple more expensive ones. I also really like the approach to entropy on the Specter

I don't care so much about big buttons on big devices and I prefer smaller size for device that can be placed in any pocket or hidden easy.

[nortwood]

The esp32 is exactly what came to my mind when I started looking at wallets again. Last batch I got were less than $4, $6 with a camera. That being said then you've got bluetooth, wifi, and espnow to contend with. They're designed to be easily connected to. I think there are some read only wallets that use them on github. With that in mind I found his presentation on the board itself insightful:

(about 7:45min in)
https://www.youtube.com/watch?v=AgOqTGeDrac

The limitations of the board, particularly the chip in the center are clearly outlined. This is why by default the device never stores the seed. It's either entered manually or in a secured element. I've yet to get one, and will need to print a different case when I do because with the free one I printed I do have access to the port for it. Same with the SD card. Didn't exactly think that through.  

Overall, I've found the device to be pretty awesome and easy to use. The QR reader works really well, it's easy to use in every way. It does suck that you can't scan the QR code on the device through tor (tor disables camera access). That's really got nothing to do with Specter though.  

I've spent way more time trying to get my regtest up than anything else so far. I've minted coins but I'm having issues sending them out.

I look forward to being able to use the java cards. There is an issue there as well though. You have to chose either to encrypt the java card, at which point the device is required to ever unlock the card, or have a java card that's password protected only (not encrypted) but can be opened with any device. I doubt I'll encrypt. It would suck to lose or break the device. With password protected cards at least I can build a new device if the first one is lost or stolen. I'll update when I get a chance to play around with a card reader.