Create your own metal seed key backup

in LeoFinance4 years ago (edited)

If you are storing your crypto in your own hardware or software wallet (Which you should be!) you must remember up to 24 seed words to recover your wallet.

These seed words are all that stand between you and your crypto if you need to recreate your wallet. There are many ways to back up these seed words, each has its benefits and drawbacks.

It is typical to store your seed words on paper somewhere perhaps even split between multiple locations. If anyone gains access to these seed words they can gain access to your crypto.

While theft is a major concern, destruction is another. The most obvious is fire and water for paper wallets. A popular alternative to paper is stainless steel and titanium. There are many commercial projects that can help you do this, but they are expensive and many are faulty.


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Here is an example homemade solution to store your seed words. This is relatively simple to build and effective. Keep in mind though if anyone gets ahold of it they will have complete access to your wallet(s).

Another popular option is a CryptoSteel tileset or something similar.


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These sets are not indestructible and as you can see below once they are compromised, they will no longer be of any use.


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There is a cool do it yourself option that is fun and easy to do that will provide a very high level of security against destruction. I came across this on Reddit and found a few different ways to build similar devices.

My favorite is a combination of two projects.

The primary one is Safu Ninja which you can see below.


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But swapping the nut for a wing nut as you can see in this recent Reddit post.


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While they are the same general idea, I prefer the wing nut but you should be referring to these very infrequently so it really doesn't matter all that much.

The first thing you will need is 24+ washers like these that can be found on Amazon.


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There are cheaper options, and this is just an example to get you started.

You will next need an imprinting set which also can be found on Amazon but there is a cheaper set at Home Depot if you are in the US.


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At this point, I think you know where we are going with this. You will need to tap all 24 seed words and a number to represent the position in the washers. You can use both sides like Safu Ninja does or use one on each side as the Reddit post does. Choose the type of nut/bolt combination that suits you, and store it somewhere secure like a safe.

You will need a hammer to imprint the letters & numbers onto the washers.


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If you want a complete walkthrough, I recommend checking out Safu Ninja.

Remember, if anyone gets a hold of these seed words in the proper order, they will have full access to your wallet(s).


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Really creative idea.
Now to figure out which aisle in Home Depot!

This is actually an interesting idea.

I should try it out.

24 + 1 is the best way to go. That way you can definitely store the 24 without fear and share the 1 with closest people without too much degradation of security.

24 only puts you at risk as both Ledger and Trezor can be hacked with physical access if you don't have a +phrase.

I wouldn't recommend storing this phrase along with the seed words.

Yes, I'm afraid I was pretty unclear but that is what I meant!

I use one of these....

Using a bolt, wing nut and washers is really neat, maybe I'll try that for my next one.
I did my last one using 2 3X3 inch zinc coated steel plates that are meant for joining wood. They are about 1/16 inches thick. I wrote 12 words on one side of each place and just zip-tied them together. I guess I could use bolts, glue or a soldering iron.
I didn't use the stamps, I just used a stencil and sharpie, then a tungsten-tipped engraving pen,

Perhaps a risk is they could fuse together, or with 12 it's easier to lose one. Who knows.

I hear titanium is the best material.

Got any pictures ;P

I wrote about it:
https://peakd.com/@abitcoinskeptic/securing-a-cryptocurrency-seed-phrase-on-steel

Pictures just show the engraver and the plates I used. I wasn't brave enough to put a picture of my passphrase on the internet.

In the article I linked, they do mention that engraving isn't perfect, ex, difficult to distinguish some letters and numbers (ie. B and 8), but we don't have that issue with passphrases. Also, the way the 2048 wordlist works is to help avoid confusion - lower/ uppercase doesn't matter and only alphabet is there (ok you need numbers at the beginning, but this is easy to notice).
I recommend having the list open in alphabetical order to make sure you don't end up with something difficult to distinguish or use capital letters v small ones when difficulty arises hn, rv, lI ....there are a few so uppercase is generally safer.

ex
value vs valve. (I'm not sure if both words are on the list), I had no difficulty drawing V and U differently - lines vs curves, but who knows?

Pictures just show the engraver and the plates I used. I wasn't brave enough to put a picture of my passphrase on the internet.

I was just being funny. I hope you would never.

Lol, yeah the funny thing is I do have those 2 pictures. But I decided against even taking a picture of what it looks like now.

It's obvious if it is stolen, but I want to know if someone ever opened mine, then reassembled it.

I find a problem with the wing nut and washer method, someone could open it, take pictures and close it up without you even noticing, then wait for a great time to steal your crypto (or take all the time in the world to crack the 25th word/passphrase).

With zip ties and markings, it would be easy to open, but a pain in the ass to close and reassemble in the same way.

Maybe scratching or drawing something on the outside of the washers would be good cause chances are they won't notice before taking it apart. They would naturally line up a line. So you could just line up the prime numbers or something.
You could also intentionally screw up the order of the stack since they have numbers anyway (not 1,2,3, all same side up). Just store your order in email and check when you are worried for whatever reason.

You can buy stickers that deteriorate if broken, like warranty void if removed. In fact some of the commercial options use this.

Check out the 10 second video for the Crypto Key Stack at the end of this page.

https://cryptokeystack.com/

The home printable paper wallets also use stickers you can purchase.

That's good, unique tape is best, in case, they have the chase to come back after ordering it on Amazon.

Crypto key stack is actually where I got my idea from. I just thought buying 1$ steel plates was cheaper...and less suspicious if people are checking out my mail. Building a deck, eh? Writing your name on your tools, eh?

I think the more measures you take the better. Sadly, chances are if it gets compromised it is someone you know and trust.
When I worked in IT, often it would be relatives who were scammed into thinking they were helping along with the occasional bad apple.