Wearable Keys

[SaltySpitoon]

Hey guys, as a few of you may know, Wearable Keys has been on my todo list forever. I finally got around to doing some tests, and have finally got decent results so I figured I'd share. Of course you can expect better in the near future as I figure out a few technical details that I'm missing.



I really liked that Charlie Shrem had his private keys inscribed into the inside of his ring, but I had never got around to figuring out how to do it feasibly. Now that I've figured out how to do it for myself, assuming I get better at it, I'll probably end up making wearable keys for the public. Rings are simple enough, I've got an idea for a pendant that sort of resembles the 25 BTC Cassascius coin, as that was what I planned on doing with one if I ever got one.

Pros:
Metal inconspicuous paper wallet that you habitually carry, fire resistant, and convenient.


Current problems:
I've still got a bit of research to do on key formats. Preferably I don't want to engrave 64 characters. I know that minikey formats exist but I'm going to have to figure out what the best option is.

As far as security goes, there are a few issues. Charlie's ring was lacking one character from the inscription that he just remembered. I think inscribing encrypted keys is probably also a winning idea. I have a few ideas on how to obscure the keys once inscribed, but they are really stupid as of now. If I decide to prefund them and give different pieces different BTC values, that would probably have to go on the pendants as it'd be kind of stupid to get a ring that isn't your size that you can't conveniently carry around.

Anyway please let me know what you think. I welcome the harshest of criticism and the toughest questions, because they may lead me to figure out a few solutions to the current problems.

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[JanEmil]

Could be RFID to get the key and the password is inside the ring.

[Mbitr]

Really really love this idea. I AM going to buy one when fully developed.
Will you be doing gold and  silver ?
Haven’t really got any suggestions to help on the security side, but my only advice is to keep it as simple as possible !
Love it 😊

[SaltySpitoon]

Could be RFID to get the key and the password is inside the ring.

I'm not entirely sure how I would place an RFID chip inside. I'll look into it, and if I figure that out I'll try it out, but that would likely remove the flame resistance.

Really really love this idea. I AM going to buy one when fully developed.
Will you be doing gold and  silver ?
Haven’t really got any suggestions to help on the security side, but my only advice is to keep it as simple as possible !
Love it 😊

Yup, I make the rings from an alloy of Argentium silver that I've created. I can also work with any karat of  yellow gold, though I've not yet mastered white gold, but that shouldn't be a problem in the short run. I haven't made anything out of platinum yet, but it shouldn't pose any problem. I just need to source platinum in that case.

[krogothmanhattan]

If your going to place private keys..then BIP38 encrypt.

Done it here and the btc is still there after 2 years online for all to see. https://bitcointalk.org/index.php?topic=3315347.msg51282487#msg51282487

[SaltySpitoon]

If your going to place private keys..then BIP38 encrypt.

Yeah, I'm absolutely on board. I want the keys to be accessible to the owner, but not too accessible since its difficult to actually obscure the keys. I have an idea that would involve filling the engraved keys with a same colored, lower melting point alloy of the ring material, that would require you melt the filler material out to expose the keys, but there are quite a few things wrong with that plan.

I don't know how inconvenient it would be to import an encrypted compressed key format. I shall find out!

[SaltySpitoon]

Well, I've got a good understanding of how engraving keys that the end user gives to me securely, but I still can't figure out if there is a way to BIP38 encrypt Minikeys. It seems to me like the format isn't recognized as a private key and can't be encrypted. I'm not sure if thats a defined limitation or just a personal problem.

I ran into one other issue with upper/lowercase letters. I had planned on just using a smaller font size for lowercase letters, but that is confusing for things like R vs r . My engraver is a jig with a carbide engraver bit that follows hand made movements. I use a template to keep the font and size consistent, but I do not have a lowercase letter template and I'm having a bad time finding one. I'll probably just mill one myself, but thats a pain. Anyway, I'll keep you updated!

[Chris!]

Well, I've got a good understanding of how engraving keys that the end user gives to me securely, but I still can't figure out if there is a way to BIP38 encrypt Minikeys. It seems to me like the format isn't recognized as a private key and can't be encrypted. I'm not sure if thats a defined limitation or just a personal problem.

I ran into one other issue with upper/lowercase letters. I had planned on just using a smaller font size for lowercase letters, but that is confusing for things like R vs r . My engraver is a jig with a carbide engraver bit that follows hand made movements. I use a template to keep the font and size consistent, but I do not have a lowercase letter template and I'm having a bad time finding one. I'll probably just mill one myself, but thats a pain. Anyway, I'll keep you updated!

I always meant to do something similar, although I just bought jewelery stamps. I had the exact same problem where I couldn't find lower case letters. I did eventually find some, but in a weird font & 3x as expensive. I thought that would be funny to share. Why the hell are lower case letters so hard to find!? Anyway, this is an awesome idea. Many kudos from someone who meant to do this but never went through with it.

[SaltySpitoon]

I always meant to do something similar, although I just bought jewelery stamps. I had the exact same problem where I couldn't find lower case letters. I did eventually find some, but in a weird font & 3x as expensive. I thought that would be funny to share. Why the hell are lower case letters so hard to find!? Anyway, this is an awesome idea. Many kudos from someone who meant to do this but never went through with it.

Stamps are doable to, but its really difficult to get them uniform. You either need to stamp the metal while its flat and hope that you don't leave any toolmarks while forming, or get the weird letter punches with a curve to them. Those are super expensive. I tried using stamps a while ago and I'd get 10 characters in before stamping something at a 2 degree angle off of what it should have been and ruining the end product. I might try to just use smaller font and just make it really obvious the difference between capital R and lowercase R by size, but I'd really like to find a lowercase solution instead. I'll get one completely finished and then decide from there whether its worth getting a jig plate milled.

Anyway, I'm at the point where problems that I'm running into are minor inconveniences, not major problems, so I'm thankful for that. I'm ordering some additional golds on monday so I can play around with alloys. I know its awful stupid... but I have a theory on making purple gold work.

From Google Images Purple and White Gold:

[SaltySpitoon]

Daily Update!

I've had pretty much nothing but bad ideas, but the sooner I get them out of the way, the quicker I'll get to the good ones!

I have two things in mind, first custom provided encrypted keys that are sent and engraved into the piece. The keys can remain exposed as an engraving since they need a password anyway, and the piece just serves as a damage resistant and discreet paper wallet.

The prefunded and obscured model are likely more desirable to collectors as they'd have a resale value similar to funded coins. I'm not super thrilled about knowing the private keys, as to date I still don't entirely trust Casascius etc, but it'll likely come to it if I can figure out the last piece of the puzzle. My idea was to physically melt a slightly lower melting temperature alloy of the main material into the engraving, so to expose and redeem the keys, you'd need to physically melt the covering metal. With that idea I run into the issue of not everyone owning a torch capable of doing it, and a capable jeweler being able to re-cover the keys after exposing them. That also excludes the plan to weld two pieces together to require one to break the piece in order to redeem the keys for the same reason.

I can still go ahead with the encrypted private key plan, though I'm still stuck on obtaining encrypted minikey private keys.

[Chris!]

That also excludes the plan to weld two pieces together to require one to break the piece in order to redeem the keys for the same reason.

Maybe a spinner ring? That or a spinner ring with a small decorative hole so it never shows the whole private key. You could easily access the private key by spinning it around and writing down the private key 1 letter at a time?

[SaltySpitoon]

That also excludes the plan to weld two pieces together to require one to break the piece in order to redeem the keys for the same reason.

Maybe a spinner ring? That or a spinner ring with a small decorative hole so it never shows the whole private key. You could easily access the private key by spinning it around and writing down the private key 1 letter at a time?

Its a neat idea design wise, and something I'd definitely be interested in doing. It doesn't really solve the problem of making it 100% apparent that someone has observed the keys and they are no longer secure. Like I said, this issue is just for incrementally prefunded pieces should I decide to make them.

I'll just stick to personal wallets until I figure out a better method.