This is an opinion editorial by Shawn Amick — all ideas and suggestions are fully the authors and never an official Bitcoin Magazine endorsement.
Cryptotag not too long ago allowed me to check considered one of their newest merchandise, Odin, which is a singular product which means to safe self-custodied keys with a set of titanium, laser-etched hexagons that every retailer a partial key (a “share”) that is break up utilizing Shamir Secret Sharing.
Shamir Secret Sharing
Shamir Secret Sharing permits you to break up your seed into m “shares” the place any n of them can be utilized to rebuild your authentic seed. But anybody holding lower than n shares doesn’t also have a partial copy of your seed. This additionally means which you could lose m – n restoration shares and nonetheless give you the option to rebuild your seed. A extra detailed rationalization is obtainable right here.

Image Source: Trezor
In order to use Odin, you’d want to choose the right amount of phrases per restoration share— on this case, that will be 20 phrases per share, as Odin solely helps a 20-word capability.
Shamir Secret Sharing generates a random phrase for every of the 20 phrases included in a share. The phrases generated are pulled from a predetermined record of phrases which have been hand-picked to optimize for safety (the glossary might be discovered here).
Each phrase has a corresponding quantity. For instance, “academic” is correlated to the primary. This quantity is represented as 0001 within the SLIP-0039 (Shamir Secret Sharing) Word List that was despatched with Odin.
Shamir makes use of a setup comparable to multisig, besides as an alternative of making a pockets from a number of seeds you simply have a single seed that may be assembled from a number of restoration shares. The Shamir setup consists of the next parameters: Total Shares and Thresholds.
Total Shares: The variety of restoration shares to be created for a selected seed. For occasion, if a buyer wished there to be a complete of 5 restoration shares, they would create 5 Total Shares. We will return to the precise course of of making these components additional beneath.
Threshold: The crucial variety of restoration shares required to give you the option to rebuild your seed. Continuing with the instance above, if we have now 5 Total Shares, we would need to set a Threshold of three. This implies that of the Total Shares (5) that exist for this pockets, we solely want three of the restoration shares to reassemble our seed.
Odin
The product is packaged in a sizeable black field with the phrases “This is for the HODLers” inscribed on it. In the field you’ll discover the titanium hexagons, their accompanied silicon sleeves, an anvil (used to maintain the hexagons in place to engrave later), a HODL BODL (very cool water bottle), matches, ear plugs, a high-quality heart punch (for engraving), setup information, some snacks and, in my case, a Trezor {hardware} pockets.
The titanium hexagon stands at 0.87 inches tall, 4.7 inches lengthy and 0.98 inch large.
While it matches simply right into a pocket, I wouldn’t suggest carrying your keys with you in all places you go for folks to see, even when the silicon sleeve with “Cryptotag” embedded on it seems to be nice.
Odin is glossy and compact in design. The titanium hexagons used for creating the restoration shares are black with 4 sections per aspect.
One aspect reads: Total Shares, Threshold, Share Number and Wallet Number (in case you have a number of wallets, you possibly can designate which pockets that individual hexagon applies to).
Each of the remaining 5 sides has 4 numbers. For instance, the primary aspect is numbers 1-4, then 5-9 and so forth. Each quantity has 4 digit grids beside it with the numbers 0-9 in every. The digit grids are used for the Shamir backup as a method to encode every phrase within the restoration share.
Each phrase has a corresponding quantity from the glossary. For instance, “academic” is phrase primary. For Odin, this quantity is represented as 0001. Remember, there are 4 digit grids for every quantity. Therefore, if the primary restoration share phrase is “academic,” this is how we’d proceed:
On the primary part of the hexagon represented by a big “1”—this means it is recording the primary phrase of the restoration share—you’d punch “0” within the first three digit grids after which “1” within the fourth and closing digit grid for the primary restoration share phrase.
Now what do I imply by punching a quantity? How does it truly get related to the right quantity on the digit grid?
User Experience And Guide
Assuming the patron has zero expertise with {hardware} wallets or self-custody, it wants to be stated that this course of was exceptionally simple and solely mildly time-consuming.
Once you obtain the setup information, the primary pages stroll you thru the straightforward steps to setup a Shamir Secret Sharing backup supported by means of Trezor’s {hardware} pockets, (Shamir has restricted assist from different {hardware} wallets).
The steps have been easy. First, join the Trezor pockets to your laptop through its USB cable. You shall be prompted by the system to go to Trezor’s web site the place you can be requested to obtain Trezor’s software onto your laptop. The obtain is fast and straightforward.
Once the applying is up and working, the pc will immediate you to set up a firmware improve on the system. Once accomplished, the applying provides you with two easy selections with photos. Do you desire a regular backup or Shamir?
After clicking Shamir, Trezor walks you thru some easy steps organising a pin quantity, the technology of every share and specifying the brink and pockets numbers mentioned earlier. It’s extraordinarily simple and user-friendly.
Once the quantity of shares is picked, you’ll generate the phrases related to every 20-word restoration share for the variety of shares chosen. Trezor will immediate you to write these phrases down—manually!—and can remind you to ensure that it is not digitally saved anyplace.
This subsequent half is the place issues go somewhat gradual. In the goodie bag Cryptotag despatched you’ll discover a “conversion sheet” for every hexagon bought. Here you’ll discover a slot for all 20 phrases related to the restoration share of every hexagon. Below the place you possibly can write the phrases, you’ll discover 4 bins beneath every phrase. Simply write the phrases down, ignoring the bins beneath the house for the phrases.
In the field you’ll additionally discover “SLIP-39 Word List”. Each phrase, as I discussed earlier than, is represented by a four-digit quantity. Locate every of your 20 phrases per share within the glossary and write the corresponding quantity down beneath the phrase.
Now we find the middle punch instrument. Remember, these hexagons are titanium, which implies so as to depart a mark it takes some stress. This is additionally why Cryptotag sends earplugs. I didn’t really feel the necessity to use them, however the neighbors may need appreciated it if I gave the earplugs to them.
For every phrase of the Shamir backup, you’ll punch the four-digit quantity into every part.
This course of wants to be repeated for all 20 phrases for every hexagon getting used (one per restoration share). It takes a while, however as soon as it is full, you’ll have a fire- and waterproof, laser-etched titanium backup able to being dispersed in a method that is assured not to damage you if one is misplaced or stolen.
Conclusion
Odin is a sensible and sturdy answer to assuaging a lot of the priority round defending your keys (seed phrases). I’m thrilled Cryptotag allowed me this chance to grow to be a fan of their product. That being stated, I did have some issues.
While anybody holding onto a restoration share for you can lookup the general public record of phrases after which decode every phrase from the punched numbers on Odin, it will nonetheless solely lead to one share being compromised which implies that the brink wouldn’t be damaged, sustaining the protection of your keys. This requires clear administration of your shares and trusted events (if relevant), however that’s hardly completely different out of your customary self-custody answer.
The heart punch used to engrave every digit on Odin wasn’t excellent, however I wasn’t depressing. I managed to get all through one hexagon earlier than I had points with it. After that, the mechanism that holds the tip in place started to shift. The repair was a easy motion to return in place, however I did have a concern that it’d cease mid-process.
The setup information isn’t worded for superior customers, nevertheless it additionally isn’t worded for inexperienced persons. As talked about above, I reached out to make clear definitions and processes simply to ensure. I’d have appreciated for the information to be a bit extra detailed.
The digit grids used to punch within the numbers related to every phrase are actually small. I’m certain this is by design to maintain the product compact. However, I did discover myself not being fully proud of the mark I left which brought about me to simply add one other mark.
The glossy design matched with immense sturdiness affords peace of thoughts for these wanting to take the additional step in safety with a daring aesthetic that is onerous not to like. Upon testing my Trezor restoration course of, I discovered it labored high quality, with the plain word that any mistake within the creation of the shares would lead to an error upon restoration. All that being stated, this is a product for HODLers who admire aesthetics and have extra cash to spend. I’d fortunately do it once more, nevertheless it’s hardly a necessity.
This is a visitor publish by Shawn Amick. Opinions expressed are fully their personal and don’t essentially replicate these of BTC Inc or Bitcoin Magazine.