BitSafe Hardware Wallet Development

[Darktongue]

 This is very neat and I'll more then surely purchase one. However fine tuneing ky RaspPi into what I now use as my hard wallet has been It's own labor of love.

I wanted something I could store all my coin on. abd generate keys for all the active and even dead coin. I've also setup a way to generate abd print paper for each coin. I don't plan on takeing my device outside the home. any coin I do take with me I gamble with via my android device. I only take enough with me incase an uncanny deal or item is up for grabs and I catch on to it while mobile.

basically I never carry more BTC then I have in USD in my wallet most if not all the time.  Now this may sound like overkill or complex bullshit but I stuck the board in the wall behind my TV in our family room. I built a nice mount for it and ran the power cord to an outlet where I installed a typical three prong socket with the added bonus of usb. I can remove the board from the wall clean abd clear as the mounts ride on ball bearings I had a faceplate made as well for cosmetics and when not in use a picture hangs over the entire setup.

Basically the whole project for me was the pipe dream of owning a wall safe behind a picture like in all the mafia flics. I was able to get my wife to follow along as It's super easy to plug a different SDHC card and make it a fantastic media center.

But that's just my love for my chunk of the Pi. again not saying this isn't and will not be a welcomed item in my efforts to keep abd spend crypto moneys.

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[allten]

2) This price does not include a PicKit 3 which is a must at this early level of development: $45.00 + Shipping
http://www.microchipdirect.com/ProductSearch.aspx?Keywords=PG164130

It is possible to avoid using a PicKit 3. If the dev board is loaded with an appropriate bootloader (eg. http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en554836), it should be possible to program the device using the on-board USB port.

What the PicKit3 is useful for, is if:

• You want to develop or modify the bootloader itself (if you mess up the bootloader, you could brick the PIC32, in which case you need a PicKit3 to recover).
• You want good integration with MPLAB.
• You want to use debugging features like breakpoints, watches etc.

This is why it is so nice working with "someone" vs. alone. I knew it was possible to make a bootloader app with firmware, but I had no idea how feasible it was to produce in the short term. How long do you think it would take to have it ready and working? Looks much easier than I thought with that app note and all the source code available. This is really great news.
As soon as there is a working boot loader prototype, I will surely make it available to order.

 

[allten]

I'm not sure if the ICD3 will work. I'll have to look into it. If it does, you will still need an RJ-45 to a 6-pin female pin header adapter.

It looks like the ICD3 will support the PIC32 from microchip's website. Also, I have made lots of custom programming headers, since RJ-11 is a horrible choice for a programming header.

Your offer to help assembly is extremely appreciated. Stencil printing too; I'm envious, but this is really great. Whereabouts in the world you located? I'm in Arizona.

I'm in TX, whois paybitcoin.com + google if you must know  ... At work we do a bunch of prototyping and custom engineering work. Mostly with Linux/Android now on armv7a using CPU system-on-modules since our apps got more complex, but used to be all PIC18. We started to move off to other architectures (Cortex-M3) since MPLAB is such a bad IDE, and mostly the 4096 byte RAM limit with PIC18s. I haven't used the PIC24 or PIC32 though.

That's a cool rendering of a hardware wallet.

You mentioned you had a stencil printer; when I have everything ready to send, would you trade a stencil for a PCB and components?
Not sure how much a stencil runs; so, maybe that is unreasonable.
If you wanted to help in assembly, I would love to pass the savings on to others. 

[paybitcoin]

That's a cool rendering of a hardware wallet.

The full rant is here: Yet Another Hardware Wallet Proposal? after a lot of thinking about viable mass-market solutions.

You mentioned you had a stencil printer; when I have everything ready to send, would you trade a stencil for a PCB and components?
Not sure how much a stencil runs; so, maybe that is unreasonable.
If you wanted to help in assembly, I would love to pass the savings on to others. 

We have this printer, for applying the paste evenly. We currently buy stainless steel stencils from Stencils Unlimited for $125 that work very well. You can also get cheaper stencils in Mylar from them, and also from Pololu. I haven't tried the mylar stuff, but it is probably suitable.

I'm pretty sure I could help out with the assembly. Maybe a trial run of 5 boards or so on a weekend to see how it goes? How many PCBs are you planning on ordering? Are you going to be panelizing them?

[someone42]

The different generators have their own advantages and disadvantages.

Could you please elaborate more on this topic? Just to make sure we are on the same page here ...

Here's my current understanding. It's subject to change, since analog circuits can work differently in the "real world" vs. theory.

Atmel CryptoAuthentication chip
Good: Tiny, integrated solution. This means board layout is easy (no touchy analog sections to worry about) and device size is a bit smaller. It is very likely to Just Work.
Bad: As slush has pointed out, Atmel don't say how it works. They say it's "high-quality" but don't justify it. There's no access to the raw samples, meaning that it could fail to produce enough real entropy, though it still outputs seemingly random bits.

Thermal noise source
Good: the existence of thermal noise is guaranteed by fundamental physics. The amplitude can be reasonably well estimated a priori. The particular design used (a differential amplifier) rejects common-mode noise somewhat. Noise characteristics are simple (white, Gaussian).
Bad: requires a lot of gain, which can provoke oscillation. High-valued resistors mean that it's sensitive to parasitic capacitance; this can cause bandwidth, unwanted feedback or (external) noise feedthrough problems. Requires board space for 3 op amps.

Zener noise source from zener diode
Good: components widely available. Requires less op amps than thermal noise source. Noise characteristics are probably distinctive, which makes it easier to distinguish zener noise from everything else.
Bad: noise amplitude is tiny, requiring even more gain than thermal noise source. Noise amplitude probably varies between components, complicating mass production. While zener noise is generally unavoidable, most manufacturers strive to reduce it.

Zener noise source from voltage reference
Good: Louder than zener diode. Probably more consistent than zener diode.
Bad: Once again, noise is usually unwanted by circuit designers, so chip designers try to minimise it. We had to look around for a chip which was noisy enough (the LM385 is used, which is an old chip). Voltage references aren't designed to be used as noise sources: they're designed to be used as voltage references. Slightly more expensive and bigger than zener diode.

Oh, I forgot this one: most microcontrollers have multiple independent oscillators (eg. crystal oscillator and internal RC oscillator). If both oscillators are run simultaneously, they will drift apart randomly. This drift can be measured using a suitable interrupt handler.

Drifting simultaneous oscillators
Good: you get it for "free": no external components required.
Bad: uncertain quality of random bits. Throughput is quite slow - last time I tried, I was only able to get a few hundred bits of (unknown quality) entropy per second.

Some resources:
The zener noise source circuit we borrowed from: https://mywebspace.wisc.edu/lnmaurer/web/minirng/RandomBit.jpg
Comparison of noise sources: http://ciphersbyritter.com/RADELECT/MEASNOIS/NOISMEA1.HTM

[allten]

Bitsafe Hardware Wallet Development:

New Thread with new discussion and direction:
https://bitcointalk.org/index.php?topic=152517.0