Bitcoin Forum

I hope this is OK to post here.  I found this on Etsy and thought it was an interesting concept, a 3d printed coin:

https://www.etsy.com/listing/1228356797/bitcoin-wallet-with-unique-serial-number?ref=cart

I ordered 2 out of curiosity and wanted to share for others to see. I was wondering if anyone knew of the company.

Thanks!
Mark

saw these thru some where else - interesting. very expensive printers used for this as well. I would not buy their loaded ones though. just the unloaded.

You mean a concept like this?  ;)

https://bitcointalk.org/index.php?topic=5389190.msg59974293#msg59974293

But I do like the novel concept of the spokes.. ordered a few...never to load. Just as a empty wallet. Anytime you load anything from unknown sources....you are playing with fire with your precious Satoshi.

I agree, I was a little weary how secure the private keys are with their buyer funded ones, as it appears the public key is printed into the coin itself.  I sent them a message asking to clarify their process.  I was hoping someone here knew of the manufacturer and any thoughts on their trustworthiness.   In any case, I usually only fund keys with a nominal amount of Satoshi just in case. :)

I'm curious what production quality will look like... pix & video are renderings. If not, could someone please tell me which 3D-printer can do that resolution?

 Will post pics once I receive mine

this process is not like typical 3d printing as seen on yours krogoth - it does a layering system where it lays down a layer of "powder" or "filament" like dust and then uses lasers to precisely target and melt the filament together. once completed you then have to sweep away all the left over filament from the item.

My guess is that somewhere during the process they pause it and add the key and then continue the print - thus truly enclosing the key and requiring it to be broken to expose the key.

I reached out and asked a few questions and got a prompt response:


Hello Mark, we have no third party evaluation of our process at the moment.
Our security concept is the following: running one single script "OBOLITE MINT" for generating encrypted files containing private key, adress, converting keys into QR code and serial number as picture files; using said files for texturing with preset OBJ and MTF, encryting the same for an also encrypted print job file and deleting print job file after printing. At the moment we sell so called pure wallets at Etsy. At our own shop obolite.com we start to sell wallets with small amounts of bitcoins and some altcoins (up to 15 USD/EUR) for people with minor interest in peer-to-peer-technique. Regarding the physical safety: It is not possible to scan the coin via x-ray to get the secret key. Furthermore, there is a nice en-passent feature from the printer itself: a thin layer of polyamid powder sticks at the inner QR code (which contains the private key). So I think its difficult to manipulate the coin as made them look like locked if once broken. In the future, we try to implement some optical features to prevent any counterfeiting.
The sold coins come from the pinter as they are (with some sand jet cleansing). However, we think to use pearl shooting for a smoother surface. At present we have a more or less rough finish (which I call sandy finish at Etsy).
Best
Ingolf


I sent him a link to the board, I hope he participates!

These look like cool coins that appear to be well done.  Nice work!

If I were to be the guy to sound an alarm on these types of coins, I would say to be careful of loading 3d printed coins like this with funds.  I'm not even hinting that anything is amiss here, but if 3d printed coins is a trend that's going to continue, people should be aware that the cost barrier of creating large precious metal coins keeps a lot of scammers out of the space.  They don't (often) have the funds necessary to have dies made and do a large precious metal mint just to attempt a scam.  However, 3d printed coins can be created for a fraction of the investment, making them an attractive attack vector on this community by scammers.

Again, these coins look cool and I'm not saying there's any reason to avoid them.  However, it is likely only a matter of time before someone starts selling loaded 3d printed coins with the intent of clearing out all the wallets.

my concern would be the keys - they generate them and save them to files and convert to print files then send to printer and then delete - that means there are at one time possibly 2 files containing the keys and they are deleted. I wonder if either the machine that generates the keys or the one that prints them is ever online.

Posting new finds is strongly encouraged...thanks for sharing.

Since, most printers are sort of going the online route these days, I think it would be best to assume that. Ideally, people that want to be selling these types of things, can prove the process rather than just saying the steps they take. Even, when it comes to highly trusted users in the space, it only takes mishandling that process to potentially unknowingly compromise it. Things like printers having storage, and storing previous files, then later selling that printer, something that someone might not at first thing of.

So, yeah I'm probably in support of avoiding funding these, unless there was a provable way of generating them, and manufacturing them, which there probably isn't in this specific scenario or is probably too much effort for the potential sales they could get.

Again, I'll echo the sentiment here, I'm not accusing anyone of anything, I just think it's good to be as security conscious as possible when it comes to things like this. Personally, I wouldn't want a large amount stored on a physical thing like this anyway.

I got them in the mail yesterday, they look great.  I ordered 2 off Etsy and then directly inquired for two loaded coins.  Overall a cool novelty:

https://i.postimg.cc/DwbqQFbY/IMG20220616153529.jpg

I agree with all the concern people have shared over security. I wouldn't use these

Gotta say these look super cool though, very creative and high quality.

Do they number these or mention a commitment to a limited mintage?

Steeley

I reached out and got a few questions answered, here was his correspondence:

Dear Mark,

thank you for your mail 5/27. Of course you can order BTC coins with denomination from the website shop. I suggest you to pay with BTC.

Than I wait for shipping the Etsy order and but the two orders together in one package. Please be aware that at the moment we should expect very long shipping times. DHL published up to 60 (!) days for shipping (due to Corona issues at European and/or U.S. harbors).

I am also sending you a link to a video at google drive.

https://drive.google.com/file/d/11LD5OKj7yaKzaEaVU9Bv9elvCFCHbO9G/view?usp=sharing

The video shows how to open an Obol and how to expose the inner QR code. You can see the powder layer, which I call the security layer. And also how to remove this layer. The QR code is very robust as the dye additive stains the nylon material (PA 12) about 70 microns deep (which is quite a lot).

With regards

Ingolf

Ingolf Bode

mod note: PI redacted upon request
https://obolite.com/


In any case, the denominations that are on it, I am not too concerned.  I agree completely, I would not use them to store any significant value of BTC at this point.  However, as a novelty they are really cool.  I might give them for a Christmas gift to some nephews.  I doubt these will be limited, but it is a good question.  Perhaps we can get him to join the forum (I mentioned it to him) and be part of the community.

Wow thats really interesting on how to open the "coin", you have
to actually destroy it to get to the QR code. There wouldnt be a
chance of getting a fake. The only concern would be the generation
of the wallet address and keys.

When I first saw them I thought they looked a bit cheap and a bit
gimmiky but the photo above and the video make them look less so.

Mine arrived today...I placed them next to my own plastic coins for reference



https://talkimg.com/images/2023/05/14/blobdada78c28ee25e42.png

Many thanks to Mark Zeller for the invitation to this forum of collectibles!

I'd like to report a few technical considerations that led to our Obol wallet.

The token shown is an evolution of a technique that involved breaking a plain nylon coin in half to access an inner code. https://obolite.com/wp-content/uploads/2022/06/Splitcoin4_2018-600x334.png

The coin would have been a possible alternative to the metal piece with paper code plus adhesive seal.  As is well known, the latter could have been spied out unnoticed back in 2013 (CoinDesk, Aug 13, 2013 "Defcon hackers crack physical bitcoin coins").

Unfortunately, this predecessor showed that the code, which was formed as a raised 3D font, could be seen very well in the CT scan. Further, the token also had to be quite large in diameter for the elongated alphanumeric code sequence to be printed in sufficient quality.


https://obolite.com/wp-content/uploads/2022/06/Af-916-2018_Munze_3308_vorne_29s-600x315.png

Anyway, it was possible to use additive manufacturing for sealed codes years ago, provided you liked big Mickey Mouse tokens and CT scans of the private key didn't worry you.

Are these unlimited mintage or capped at all? Looks pretty awesome to me and was gonna grab some. Just figured Id ask first

Still ordered few Coins  ;D

Just coated with a different printer (Mimaki), still a bit wet but here is the first result:

https://drive.google.com/file/d/1eBSnZWLpySKb0Kj2thQ-e4xb33QvtCwR/view?usp=sharing (https://drive.google.com/file/d/1eBSnZWLpySKb0Kj2thQ-e4xb33QvtCwR/view?usp=sharing)

Please let me know if you're like it & interested to get some of this kind of print.

sharing your picture here so everyone doesn't need to go thru the link

https://i.ibb.co/T1CjbQ2/image.png (https://ibb.co/hcqQZG9)


I need to get some of these soon.

With a bit of development, we could make the Bitcoin Coin much smaller.

https://drive.google.com/file/d/1IGpS2MN89_z2QuH4N4MmeRJFwuZeHAtz/view?usp=sharing

There will soon be Bitcoin Coins as small as 20 mm in diameter. The nice thing is that very little nylon material can then be used, which means that the physical tokens can be produced very cheaply.

The picture shows a few levels with 20, 22, 24, 26 and 28 mm diameter. Next to it is one quarter dollar, one cent and one dime for size comparison.

I would be very interested to know which size(s) you would prefer. I look forward to your response.

@MoparMiningLLC - Any chance of doing a group buy to save on shipping?   I would definitely be interested in some more.

Dime to penny size would have my interest, especially if they could be made cheap. It'd be cool to be able to buy them in stacks with low denominations and hand em out for holidays or to get people started in crypto. It's always rough with physical coins because they make so much more sense to people who aren't involved in crypto but there's always such a premium on them that it never really makes sense to buy them to give away. Just my 2 sats on the whole thing :P.

P.S. bought a bunch of these a while back and they're awesome! Just wish there was a way to get the colors more vibrant. They look a little "blurry" for lack of a better term. Keep it up! Will definitely buy more in the future.