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Topic: [ESHOP launched] Trezor: Bitcoin hardware wallet - page 257. (Read 966173 times)

legendary
Activity: 938
Merit: 1000
You're true for a hash of the full image, but fingerprint scanner actually save only a "path" of the minutiaes of the fingerprints. And using that work in a reliable way.

You mean that, for a given individual, you can always obtain the same unique "path"?

I'm not actually expert on biometrics but I've done some research on it for work and producer of scanner told me so. Low cost scanner integrated in laptop works that way, so some bank door opener. They have a small database of path and check on it it there is corrispondence. Is fast and quite secure: while a full identify request a check on lots of points (15-16 actually), just few minutiaes are sufficient for the login pourpose (with 10 point you've over 1 milion of different pattern possible, with 8  65536).
legendary
Activity: 1106
Merit: 1004
You're true for a hash of the full image, but fingerprint scanner actually save only a "path" of the minutiaes of the fingerprints. And using that work in a reliable way.

You mean that, for a given individual, you can always obtain the same unique "path"?

BTW to avoid physical coericion there is a  way, even not too difficult to implement: some times ago I've a phone with an encrypted area in which store password and pins. If you input the good password you decrypt the area, if you put a wrong one you obtain an error, but if you put a "special" one you go into a fake area with other data. Maybe is possible, for extra-paranoid implement a similar approach: one pin for real wallet, another one for another with only few BTC in it.
But again we are talking of extra-paranoid people here. IMHO slush design is more than adeguate.

That's plausible deniability, or more specifically, deniable encryption. Truecrypt does it.
I'd expect future dedicated device wallets to implement this, but as you note it's not a priority, at least not while most burglars remain ignorant about bitcoin. Smiley
legendary
Activity: 1386
Merit: 1097
does the device comes with some kind of memory?
how many addresses can be stored on it?

There's very small flash memory on the device (256 kB for code and data), but device don't need to store addresses on the flash. It uses deterministic wallet approach instead, so even device with 256kB memory can handle unlimited amount of addresses.
sr. member
Activity: 262
Merit: 250
does the device comes with some kind of memory?
how many addresses can be stored on it?

legendary
Activity: 938
Merit: 1000
Only better way is to replace the password with the hash of a biometric scan (fingerprints maybe) but in this way cost are higher and not all devices can support it.

Biometric scans, AFAIK, are like images. Different scans of the same individual will produce different data, which would produce different hashes

You're true for a hash of the full image, but fingerprint scanner actually save only a "path" of the minutiaes of the fingerprints. And using that work in a reliable way.

Quote
. You can compare different images to see if they belong to the same person, but if you use one of these images as an encryption key, there's no guarantee you'll ever be able to unencrypt your data.

I didn't mean use the hash as password but only as authentication method.

Quote
Of course that biometric scans could be used as an authentication method by a sophisticated device, but if the device is "physically hacked" and the biometric check is bypassed, you'll need something else to protect the data.

And, honestly, if you're afraid of physical thefts, shouldn't you also be afraid of physical coercion? What good is a biometric scan if the thief can simply force you to put your finger/eye/whatever?

As slush said before, we are not at the point where this is a reasonable threat for most of us. Hackers are a serious threat though, so we should first focus on how to protect ourselves from them first.

On that I agree totally with you: my reply was to luicon who had expressed concern about forgetting the password. If one can obtain access to both you and the device there is really few things to do.
BTW to avoid physical coericion there is a  way, even not too difficult to implement: some times ago I've a phone with an encrypted area in which store password and pins. If you input the good password you decrypt the area, if you put a wrong one you obtain an error, but if you put a "special" one you go into a fake area with other data. Maybe is possible, for extra-paranoid implement a similar approach: one pin for real wallet, another one for another with only few BTC in it.
But again we are talking of extra-paranoid people here. IMHO slush design is more than adeguate.
legendary
Activity: 1106
Merit: 1004
Only better way is to replace the password with the hash of a biometric scan (fingerprints maybe) but in this way cost are higher and not all devices can support it.

Biometric scans, AFAIK, are like images. Different scans of the same individual will produce different data, which would produce different hashes. You can compare different images to see if they belong to the same person, but if you use one of these images as an encryption key, there's no guarantee you'll ever be able to unencrypt your data.
Of course that biometric scans could be used as an authentication method by a sophisticated device, but if the device is "physically hacked" and the biometric check is bypassed, you'll need something else to protect the data.

And, honestly, if you're afraid of physical thefts, shouldn't you also be afraid of physical coercion? What good is a biometric scan if the thief can simply force you to put your finger/eye/whatever?

As slush said before, we are not at the point where this is a reasonable threat for most of us. Hackers are a serious threat though, so we should first focus on how to protect ourselves from them first.
legendary
Activity: 1386
Merit: 1097
what could happen if someone steal your device? physical access to it means lost the money?
or there is a way to enter some kind of pin with the two buttons of the device?

Device can be protected by password.

The seed (few words required to recover your coins on another device or on desktop wallet) is printed on the display during initial configuration (after you buy it). You should store this seed somewhere at safe place, so even if you lost the device or forgot the password, you can recover your coins.
legendary
Activity: 938
Merit: 1000
so i guess if you lost the password you are done right?

Actually you've to choose from high security of the system or simply of recovery of the data.
IMHO this is the best approach to security: one thing you have + one you know.
Only better way is to replace the password with the hash of a biometric scan (fingerprints maybe) but in this way cost are higher and not all devices can support it.
sr. member
Activity: 262
Merit: 250
so i guess if you lost the password you are done right?
newbie
Activity: 43
Merit: 0
hi

what could happen if someone steal your device? physical access to it means lost the money?
or there is a way to enter some kind of pin with the two buttons of the device?
The wallet in the device could be encrypted, and the password sent from the computer every time you send a transaction. That way, you'd need the device and the password to transfer money.

Haven't followed this thread, so I don't know if it's considered, but it's absolutely possible.
sr. member
Activity: 262
Merit: 250
hi

what could happen if someone steal your device? physical access to it means lost the money?
or there is a way to enter some kind of pin with the two buttons of the device?
legendary
Activity: 1386
Merit: 1097
I have the schematics for the OLED design, libraries, and BOM.
Since my purpose was to help push hardware wallet technology forward, I would hate to see it go in vain.

I'm starting to realize that this project is not about programming only, but also about logistic and management, so any help in programming part is highly welcome. We'll release everything under opensource license, so I believe this won't be about "stealing" from anyone's works....
sr. member
Activity: 455
Merit: 250
You Don't Bitcoin 'till You Mint Coin
Slush,
    It's looking nice and coming along well.
your enthusiasm you bring is surely going to make this a reality.

I have the schematics for the OLED design, libraries, and BOM.
Since my purpose was to help push hardware wallet technology forward, I would hate to see it go in vain.

If you think it would help, let me know and I will post what I have available.

legendary
Activity: 2128
Merit: 1073
@2112: I edited the post above at the same time you sent the reply, so I repost it once again. Thanks for your feedback, I think this is valuable information and I'm not so experienced in building hardware stuff. We'll have physical prototype in next days, so I'll focus on the eyelet robustness. Nothing is set in stone yet, so if I'll see any possible issue with it, we'll redesign the casing.
I sincerely wish you good luck with this. Now that I had a moment to think, I realize that most of the short-run die-casting manufacturers are working in the toy industry. They may not have the required strength information available at all. The toy industry is strictly form over function: the products are almost exclusively for display only. They will talk about surface smoothness or detail fidelity, not about internal voids or ultrasonic inspection or measuring the residual stress by X-ray diffraction.

I'm not mech-eng myself, but we used the mech-eng labs as a subsitute during the construction in the el-eng building. One can learn a lot by just passively staring at the cool experiments they make.

legendary
Activity: 1386
Merit: 1097
!!! metal? how cool is that!

We rejected plastic because we believe that our valuable bitcoins need something more robust :-). So far colored eloxed aluminium and steel are in game. Aluminium looks better as steel has cold feeling (well, it's cold storage, but... :-) ).

Plus for the future, we also have an idea of super-robustness casing for limited edition ;-). But now back to work...

@2112: I edited the post above at the same time you sent the reply, so I repost it once again. Thanks for your feedback, I think this is valuable information and I'm not so experienced in building hardware stuff. We'll have physical prototype in next days, so I'll focus on the eyelet robustness. Nothing is set in stone yet, so if I'll see any possible issue with it, we'll redesign the casing.
donator
Activity: 2772
Merit: 1019
Both are very nice, but in the original design the eyelet was much stronger.

RSA token you mentioned is from plastic where the stress on the material may be an issue. As far as our casing is from metal, I don't think we need to care about it. However we will have some casing prototypes soon, so we will see...

!!! metal? how cool is that!
legendary
Activity: 2128
Merit: 1073
RSA token you mentioned is from plastic where the stress on the material may be an issue. As far as our casing is from metal, I don't think we need to care about it.
Actually the RSA's design isn't tough. It is very resilient because of the eyelet attachment turns freely and completely avoids the shear stress.

If you are going to die-cast the metal ask the mold designer to optimize the eyelet for the manufacturability instead of just plainly making a bid for the existing design. As it is right now you'll have cracks in the left, narrowest portion of the eyelet and the possibility of voids in the bottom, widest portion. I'm pretty sure that your current design could be spin-molded properly (rotocasting). But for the standard die-casting the metal will have to flow to the widest, bottom, portion of the eyelet through the two much narrower branches. The eyelet will be under internal stress just from the uneven thermal shrinking of the metal after the casting is done.

The original design was obviously optimized for the best manufacturability: the narrowest portion is even and farthest away on the path of the metal flow. Although it does look weird to someone unfamiliar with the area rule.

Form follows function? Mind over matter?  
legendary
Activity: 1470
Merit: 1002
Hello!
Amazing work!
legendary
Activity: 1386
Merit: 1097
Both are very nice, but in the original design the eyelet was much stronger.

RSA token you mentioned is from plastic where the stress on the material may be an issue. As far as our casing is from metal, I don't think we need to care about it. However we will have some casing prototypes soon, so we will see...
legendary
Activity: 2128
Merit: 1073
Modified eyelet.
Both are very nice, but in the original design the eyelet was much stronger.

http://en.wikipedia.org/wiki/Stress_concentration

Perhaps you should consider moving the old eyelet to the new position, but maintaining the original shape that had smooth radius-of-curvature changes. It will be cheaper than the metal inlay reinforcement that companies like RSA (or car manufacturers) use in their keyfobs.

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