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Author Topic: [FREE] Free Coldkeys for testing / reviews  (Read 706 times)
krogothmanhattan
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June 10, 2019, 01:25:31 PM
Merited by yogg (1), anonymousminer (1)
 #21

Received the test card today!

I love the design and the holo pattern in the back!




I was able to load the card with 0.001btc very easily using my Mycelium QR scanner.

Once loaded I then proceeded to try and sweep the btc off the card.

To get to the Holo I noticed was not that easily done. There is a layer of thin plastic in the back covering the entire back.

Using a knife I had to cut that around the holo and then proceed to remove the holo itself before the private key was revealed as follows.

In other words, it is impossible to expose the private key without damaging the card!



Once the QR code was exposed I easily swept away all the btc in the card.

I have to say I am impressed with the design and security of these cards.

Job well done Yogg! Cannot wait to get my cards!

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yogg
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June 10, 2019, 04:23:31 PM
 #22

Received the test card today!
~snip~

Thanks a lot for your review Krogoth ! Smiley
Yes, the point is to make it very difficult to tamper with the holo and access the private key without damaging the card.

If you have any suggestions as to what I should do in another way, I'm all ears. Cheesy

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June 11, 2019, 01:25:49 PM
 #23

Received the test card today!
~snip~

Thanks a lot for your review Krogoth ! Smiley
Yes, the point is to make it very difficult to tamper with the holo and access the private key without damaging the card.

If you have any suggestions as to what I should do in another way, I'm all ears. Cheesy


  No suggestions...the card and security authentication are as good as it can get.  Wink

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June 11, 2019, 03:57:34 PM
 #24

I really like these things, I think we could use them as wallets too, and remembered me a lot of the https://bitcointalk.org/index.php?topic=5111005 bitcointalk collectible, could be waaay cheaper to implement than any metal wallet.
krogothmanhattan
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June 11, 2019, 04:43:49 PM
 #25

I really like these things, I think we could use them as wallets too, and remembered me a lot of the https://bitcointalk.org/index.php?topic=5111005 bitcointalk collectible, could be waaay cheaper to implement than any metal wallet.

  Yes they would be nice for a bitcointalk collectable. And they can be loaded as well with any amount of BTC a person chooses to load them with.
 

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June 12, 2019, 07:58:50 PM
Merited by yogg (1)
 #26

Received the test card today!

I love the design and the holo pattern in the back!

https://i.imgur.com/2qbjXAk.jpg
https://i.imgur.com/NBGHsSB.jpg

I was able to load the card with 0.001btc very easily using my Mycelium QR scanner.

Once loaded I then proceeded to try and sweep the btc off the card.

To get to the Holo I noticed was not that easily done. There is a layer of thin plastic in the back covering the entire back.

Using a knife I had to cut that around the holo and then proceed to remove the holo itself before the private key was revealed as follows.

In other words, it is impossible to expose the private key without damaging the card!




Once the QR code was exposed I easily swept away all the btc in the card.

I have to say I am impressed with the design and security of these cards.

Job well done Yogg! Cannot wait to get my cards!

Just got my card.. very nice.
Will test it shortly.

And yes.. I noticed this layer on the front side as well.
I am assuming it covers the QR code to help protect from wear/damage. Cool

Thanks yogg Cheesy

PHYSIBIT, MANTIS CRYPTOS & CRYPTO QUILTS - The best and most trusted places to shop for physical bitcoins and more!!
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June 12, 2019, 09:18:23 PM
 #27

I don’t like to give out my address on this forum for obvious reasons but these are fucking awesome yogg.

Kudos.

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June 12, 2019, 09:43:14 PM
 #28

Sorry I am on mobile and can't find the original thread yet. When are these shipping, I think I bought a couple a few months ago? Thanks yogg! Cheesy
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June 12, 2019, 09:50:55 PM
Last edit: June 12, 2019, 10:15:02 PM by yogg
Merited by owlcatz (1), krogothmanhattan (1)
 #29

Just got my card.. very nice.
Will test it shortly.

And yes.. I noticed this layer on the front side as well.
I am assuming it covers the QR code to help protect from wear/damage. Cool

Thanks yogg Cheesy

I'm glad you got it, minerjones ! Smiley
Can't wait to see results of your tests !

Yes, the durability of a physical bitcoin is a very important matter to me.
Nothing better than plain old QR codes compatible with most open-source wallets.  Cool



I don’t like to give out my address on this forum for obvious reasons but these are fucking awesome yogg.

Kudos.

Thank you very much for your kind words, LFC_Bitcoin. Smiley Happy you like our Coldkeys !
We will be launching our website soon, and will be looking to offer a store where you can purchase these with BTC or credit card.
This way, there wouldn't be a connection between your forum profile and the order.

We are a company and all details will be available soon on the website. (This week)



Sorry I am on mobile and can't find the original thread yet. When are these shipping, I think I bought a couple a few months ago? Thanks yogg! Cheesy

Hey owlcatz !
Thanks for your message Smiley

Yes, absolutely ! Thanks so much for purchasing some of our pre-orders ! You have no idea how these have helped us to go further Smiley
I was about to update the Genesis Edition sales thread with pictures of finished cards this weekend at latest. Smiley
Shipping will start next week, as planned. I will most likely contact you when your order is about to ship. Smiley

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June 13, 2019, 02:31:54 AM
Last edit: June 13, 2019, 05:50:29 AM by Sat0shisGhost
Merited by yogg (10), DarkStar_ (10), krogothmanhattan (6), Lesbian Cow (5), Halab (2), TookDk (1), bavicrypto (1), ChiBitCTy (1)
 #30

I find the prospect of mass-adopted physical wallets very exciting for a number of reasons and was fortunate to get 2 Coldkeys from Yogg for testing. Here's a description and results of my first test.

The photos below are low-res to save bandwidth. Here's a high-res album: https://imgur.com/a/a0qqmO6

Inspired by the S1 Casascius solvent hack, I decided to give a variation of that method a shot.

For this test, I decided to test 2 different solvents. Chloroform (pictured) and another non-polar solvent. Unfortunately I was out of glass syringes so I used plastic. And the smallest needle I could find.


I attempted to pierce the non-adhesive part of the hologram and inject in some chloroform, however the needle was blocked by a layer of paper/cardboard between the hologram and the private key. It also left a pretty obvious track mark (See photo below). The next thing I tried was trying to slice the edge of the hologram with a scalpel, and trying to inject some chloroform between the plastic card and the hologram. This worked to some extent, but soon, the word 'void' was clearly visible. I won't get into the details of the hologram now, but there's two layers. If the two layers are no longer adhered to one another, the word 'VOID' becomes visible. (see photo below).



Next, I decided to attack the hologram from the LEFT side using my other solvent and pretty much the same technique as above.
The second solvent was a lot better at dissolving the adhesive and I was able to peel back most of the hologram without the 'VOID' becoming visible. However, it's still visible at the edges from the original incision/prying open the adhesive to inject solvent in. I then sliced the top and bottom off with the scalpel.
Yogg promised me a "surprise" and he delivered. The private key is printed on a polymer that is different from the card plastic and almost the entire key melted (probably too fuzzy to be recoverable), as a result of the chloroform. However, as you can see in the photo below, the LEFT side, where I used my other solvent, is not melted. So I'm pretty confident that I've found a solvent that can remove the adhesive without dissolving the private key, but will test this more in the coming days.


As you can see below, the hologram is pretty mangled, however, I think if I practice my technique and stick with the second solvent, I might be able to do a much better job. I'm going to spend 4 or 5 days thinking about how to attack my second Coldkey and will a few more ideas on this one.

 I'm also going to try a few tricks to reattach the hologram without leaving too many traces (as it's pretty obvious this one has been tampered with) and will see if I can find a way to get rid of the 'VOID' text.
I have access to a lot of equipment and chemicals and am definitely open to suggestions if anyone has some. I'll also be testing some optical attack vectors and will see if I can alter the public key although it looks tough.


Below is a photo of the tampered coldkey (left) and the untampered one (right). I think after about 1 second of inspection, it's pretty obvious this Coldkey has been tampered with. Make sure to zoom in on the high res photos: https://imgur.com/a/a0qqmO6


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June 13, 2019, 08:30:21 AM
Last edit: June 13, 2019, 10:05:08 AM by yogg
 #31

I find the prospect of mass-adopted physical wallets very exciting for a number of reasons and was fortunate to get 2 Coldkeys from Yogg for testing. Here's a description and results of my first test.

Thank you very very much for this extensive range of tests, Sat0shisGhost !!
I am very happy our Coldkeys pass those security tests.
Yes, the point would be to find the way to provide the most secure ways and media for bearing crypto funds.
That'd be awesome to see Coldkeys being mass-adopted as physical crypto.

Yogg promised me a "surprise" and he delivered. The private key is printed on a polymer that is different from the card plastic and almost the entire key melted (probably too fuzzy to be recoverable)

Hah, so your first solvent actually took away the layer on which the private key is printed, right ? Then it'll only be the blank card.
That layer is very thin and fragile. It will ruin the QR code but if some malicious person tries to tamper with it, then that's only better.

So I'm pretty confident that I've found a solvent that can remove the adhesive without dissolving the private key, but will test this more in the coming days.

That "other solvant" that you used from the left looks more appropriate for this use to me, but there still is the whole work of replacing the hologram correctly, untouched (Wink) and being able to put a new plastic layer on top of that.
I am already starting to think of a solution to make the tampering with the holo much much difficult than it actually is, and quasi-impossible to re-use.

I have access to a lot of equipment and chemicals and am definitely open to suggestions if anyone has some. I'll also be testing some optical attack vectors and will see if I can alter the public key although it looks tough.

Thanks so much for bringing our Coldkeys to your lab and for all the hard work you've done Smiley

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June 14, 2019, 04:21:42 PM
Merited by krogothmanhattan (1)
 #32





To be honest, congratulations for your achievements with the above pic.
This got me thinking to find a solution that would not allow to re-use the hologram, if we imagine the case where the VOID pattern doesn't appear.

So far, this is what I found as a solution :



This way, the holo cannot be re-used if we emboss something on it.
It doesn't have to be a word. Maybe simple "BTC" or the ticker of the coin. I don't know yet. It can be solely some character.

By the way, test generic hologs were 20x20mm, but the definitive ones will be 22x22, so more space to crush something on them. Tongue

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June 14, 2019, 05:44:28 PM
Merited by krogothmanhattan (1)
 #33

That seems like a good change and a much simpler fix than anything I could come up with. If the imprinting on the hologram is unique, that'd help a lot too because it would prevent people from reusing a hologram they harvested from one card (say an unloaded one) on a different card.

The part where I damaged the hologram the most was when trying to get the needle between the card and the bottom layer of the hologram so as pictured, I'm not sure this would be more difficult. I would use the letter as a channel to help guide my syringe under the hologram. (Let me know if that doesn't make sense, it's kind of hard to explain). My intuition says it might be easier to get it in where the hologram has been imprinted.
Arrow denoting where I'd try to inject.

That being said, if you have bigger holograms and the imprinting doesn't overlap with the edge of the hologram, it'd definitely be harder.

I'm meeting with a polymer engineer this afternoon to see if we can relaminate the back of the card to mask that the hologram. I'll let you know! Also heading to the laser lab now and will test out a REALLY bright "light" (although I'm not optimistic about optical methods).
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June 21, 2019, 02:59:18 PM
 #34

That seems like a good change and a much simpler fix than anything I could come up with. If the imprinting on the hologram is unique, that'd help a lot too because it would prevent people from reusing a hologram they harvested from one card (say an unloaded one) on a different card.

The part where I damaged the hologram the most was when trying to get the needle between the card and the bottom layer of the hologram so as pictured, I'm not sure this would be more difficult. I would use the letter as a channel to help guide my syringe under the hologram. (Let me know if that doesn't make sense, it's kind of hard to explain). My intuition says it might be easier to get it in where the hologram has been imprinted.
Arrow denoting where I'd try to inject.

That being said, if you have bigger holograms and the imprinting doesn't overlap with the edge of the hologram, it'd definitely be harder.

I'm meeting with a polymer engineer this afternoon to see if we can relaminate the back of the card to mask that the hologram. I'll let you know! Also heading to the laser lab now and will test out a REALLY bright "light" (although I'm not optimistic about optical methods).

Thanks so much for your review Sa0shisGhost. Smiley
Yes, I will try to munch a little on the holos in the future, but this has to be thought of during the card designing stage.

I am curious to know how easily can the back of the card be laminated again. The embossing should make this difficult to reproduce.



/!\ Don't do this at home
I have been experimenting a little further with Coldkeys, particularly with the private key QR code.

First, I started by carving the privkey QR code with a pair of scissors and made some strip.



Then, why not, I completely cut off the QR code in two.



And the results are surprising !
This card that's been so badly damaged is still functioning !


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