BitcoinSeedSplitter

[Gabrics]

The big difference that one can backup your seed (this version) SLIP39 can't. That's why I had to write this. I would have been much happier just using something out of the box myself.

Indeed, but that's why I uploaded it to github, someone can upload it to other sites. Also binary logic is available, so I believe even a novice programmer can build a tool to merge fairly fast (probably hours/days). Only thing which is a must have the BIP39 wordlist which is safe and widespread enough.

Yes I did check out this in advance and tried to use/build a compatible solution. The BIG problem with SLIP39 that they don't backup the seed words.

With that in mind, what are the significant differences between your tool and Ian Coleman's Shamir39 tool which does the same thing - splitting a seed phrase in to split phrases? You can find his implementation here: https://iancoleman.io/shamir39/

My biggest issue with using something like this is that there is no standard implementation, so in addition to backing up each share you also need to back up the software itself, which is an additional risk.

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[o_e_l_e_o]

The big difference that one can backup your seed (this version) SLIP39 can't. That's why I had to write this. I would have been much happier just using something out of the box myself.

You misunderstand me. Ian Coleman's SLIP39 tool (https://iancoleman.io/slip39/) does indeed split a master private key (or other master secret) in to split phrases, but his Shamir39 tool (https://iancoleman.io/shamir39/) is different and does what your does, allowing you to split a seed phrase rather than a master key.

His specification is here: https://github.com/iancoleman/shamir39/blob/master/specification.md. There is obvious no cross-compatibility between your two tools since you both use different encoding schemes for things like the threshold number of shares and order/ID of each share, but I'm wondering you both generate actual share data in the same way?

[odolvlobo]

This repo also has code that will use SSS to split a mnemonic, though it is not as advanced as the others: https://github.com/odolvlobo/bip39

[Gabrics]

Indeed! I didn't see Ian's Shamir39 earlier. Will see if I can make mine binary compatible. That way we would have two basic implementations at least.

The big difference that one can backup your seed (this version) SLIP39 can't. That's why I had to write this. I would have been much happier just using something out of the box myself.

You misunderstand me. Ian Coleman's SLIP39 tool (https://iancoleman.io/slip39/) does indeed split a master private key (or other master secret) in to split phrases, but his Shamir39 tool (https://iancoleman.io/shamir39/) is different and does what your does, allowing you to split a seed phrase rather than a master key.

His specification is here: https://github.com/iancoleman/shamir39/blob/master/specification.md. There is obvious no cross-compatibility between your two tools since you both use different encoding schemes for things like the threshold number of shares and order/ID of each share, but I'm wondering you both generate actual share data in the same way?

[Gabrics]

I checked out and decided not to make this tool binary compatible to the aforementioned one for now.

The reasons:
1) Abandoned project since 2017 (Ian moved to Slip39 which is not a seed backup option)
2) The shares have no CRC which could lead to incorrect restored value as Shamir itself doesn't have CRC
3) Missing SplitID (unique ID at the beginning of each split run). This could lead to fatal issues if user error occurs. Eg. accidentally mixing shares from two splits (from the same seed) which won't re-build.
4) Needing the Shamir extra word at the beginning. This is not an error, but makes the share longer.
5) No password option

[dkbit98]

Abandoned project since 2017 (Ian moved to Slip39 which is not a seed backup option)

His Slip39 mnemonic shares tool is only at experimental prototype stages and I don't see any new commits posted since December 2019, and his latest github commits are unrelated with this.
He is still posting commits for his Bip39 tool and latest one was at the end of February, so I would not call it abandoned project.

[Gabrics]

He wrote this in 2018, so I thought it's abandoned. Anyway, I still think that the features I mentioned trump compatibility. At least for me

iancoleman commented on Feb 5, 2018
Agreed there are some inefficiencies and implementation-specific cruft that could be improved, but I'm on the cusp of decommissioning this tool in favour of SLIP-0039
https://github.com/satoshilabs/slips/blob/master/slip-0039.md

Abandoned project since 2017 (Ian moved to Slip39 which is not a seed backup option)

His Slip39 mnemonic shares tool is only at experimental prototype stages and I don't see any new commits posted since December 2019, and his latest github commits are unrelated with this.
He is still posting commits for his Bip39 tool and latest one was at the end of February, so I would not call it abandoned project.

[Gabrics]

It is open source, so it can't "just go away". You can compile yourself from github (free VS Code) and check the code too after just use the exe as long as you wish.

Indeed if you use a different software it can steal your coins, so you can follow step one.

I would use a clean install computer (without any network) and zero fill the disk after the splits has been created. I would also add a password to the seeds (so even with enough seeds + with knowledge what it is a thief can't rebuild).
I would also not print it on a printer. I would use steal plates made for seed words.

@Gabrics
What happens if your Bitcoin Seed Splitter tool is gone one day or not working? Someone could also create malicious app clone for stealing words.
Are there any alternatives we can use to restore our backup phrase and merge all splits or we are fully dependent only on your software.
This looks to me like one more single point of failure.