15 votes

Practical way to split a bip39 seed into a 2 out of 3 factor auth?

One Time Pad or XOR is an elegant and information-theoretic secure [1] way to split a BIP39 seed. It's a method simple to describe (apt for a will), easy to verify (trust only yourself) and the ...
answerevaded's user avatar
7 votes
Accepted

Practical way to split a bip39 seed into a 2 out of 3 factor auth?

One can use Shamir's Secret Sharing Scheme, but the input ASCII string must be under 128 ASCII characters in length. Fortunately, the 2048 English BIP 39 words are guaranteed to be unique from their ...
skaht's user avatar
  • 3,057
2 votes
Accepted

Disabling GreenAddress 2FA ∵ Google Authenticator doesn't generate the correct OTPs for it

The only reason I can think of that would result in the above with a valid OTP seed is invalid OTP settings (but default should work for Google Auth) OR incorrect time on the device OR invalid time (...
Lawrence Nahum's user avatar
2 votes

Practical way to split a bip39 seed into a 2 out of 3 factor auth?

My personal preferences: Stick to known-good algorithms like Shamir's Secret Sharing Scheme whose security properties are well-understood, rather than trying to invent something new. Reuse existing ...
Kevin Cernekee's user avatar
2 votes

Practical way to split a bip39 seed into a 2 out of 3 factor auth?

Here's a 3 of 5 one time pad solution with just 2 series (A is a random key, B is a random key, C is Real⊕A⊕B, Real is A⊕B⊕C. Thanks to @answerevaded, @oisyn, and @Scooper this is just a ...
Zoetic's user avatar
  • 21
2 votes

Practical way to split a bip39 seed into a 2 out of 3 factor auth?

There are at least three practical tools implementing Shamir Secret Sharing with BIP39 mnemonics: https://github.com/iancoleman/slip39/ https://github.com/unchained-capital/hermit https://github.com/...
Martin Monperrus's user avatar
1 vote

Bitcoin Core Wallet - Google Authenticator?

Bitcoin Core does not have a 2FA functionality.
Murch's user avatar
  • 75.1k
1 vote

What hierarchical deterministic derivation path is used for FIDO authentication on a Ledger Nano S?

On Ledger the derivation path appears to be 0x80553246: https://github.com/LedgerHQ/app-u2f/blob/3204324cb72eb00ad1a1919b5c0312edb3324de6/include/config.h#L22 However since the derivation path is not ...
Alko's user avatar
  • 111
1 vote
Accepted

Electrum two factor authentication

In the Electrum wallet for pc, it is possible to modify a wallet from normal password to 2fA (two factor authentication ) without creating a new wallet? No, it is not possible to add two-factor ...
Roman Kiselenko's user avatar
1 vote

Practical way to split a bip39 seed into a 2 out of 3 factor auth?

The answer by answerevaded seems the safest solution to the problem. In addition to his scale examples for "n of n" and "2 out of 3", here is the example for "3 out of 5":...
Scooper's user avatar
  • 11
1 vote

Practical way to split a bip39 seed into a 2 out of 3 factor auth?

Create a 2 of 3 multisig wallet using electrum or copay. You'll get 3 seeds any 2 of which need to be used to spend your coins. Alternatively create a 2 of 4 multisig wallet. You can create any ...
Abdussamad's user avatar
  • 2,699
1 vote

Practical way to split a bip39 seed into a 2 out of 3 factor auth?

This can be scaled up to 24 word seeds just by continuing the pattern.
Darth Lego's user avatar
1 vote

Which coins offer a 2 factor authentication feature built into the blockchain without a centralize authority?

Have a look at byteball (http://byteball.org). It supports n-of-m wallets out of the box which can be used to implement a basic 2FA mechanism (2-of-2 with your desktop and your smartphone, for example....
Hans-Martin Mosner's user avatar

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