*Deterministic* solution (i.e. no SSSS) to turn a secret into 6 shards…

[Fearless_F]

What's the best *deterministic* algorithm/solution (i.e. no Shamir Secret Sharing Scheme) to turn a secret into 6 shards—with any 2 of these shards rebuilding the secret?

[Charles-Tim]

The best is still the Slip39 mnemonic shares. It is available on wallet like Electrum and Trezor hardware wallet.

[odolvlobo]

What's the best *deterministic* algorithm/solution (i.e. no Shamir Secret Sharing Scheme) to turn a secret into 6 shards—with any 2 of these shards rebuilding the secret?

Please forgive my ignorance, but what's wrong with SSS and what do you mean by "*deterministic*"?

[ranochigo]

I'm assuming you're more concerned with having multiple entities hold shares of a secret, and in the context of Bitcoin to sign transactions.

SLIP39 which is an implementation of SSS is a good one, though it has never been formalized into a Bitcoin standard. Blakley's scheme is another form of secret sharing, though I prefer Shamir's, partly because of SLIP39's existence and also that it doesn't offer additional benefits. As far as information-theoric secure, I believe these are the two main ones.

Recently, there's a scheme called Multi-Party Computation as well. If you're going with that then might as well use Multi-sig since the latter is formalized into a standard.

[ABCbits]

What's the best *deterministic* algorithm/solution (i.e. no Shamir Secret Sharing Scheme) to turn a secret into 6 shards—with any 2 of these shards rebuilding the secret?

Please forgive my ignorance, but what's wrong with SSS and what do you mean by "*deterministic*"?

I believe he means the output is always same. AFAIK some SSS tool (such as https://iancoleman.io/shamir/) would generate different output if you use exactly same input on different occasion.

[pooya87]

Is deterministic Secret Sharing Scheme even possible? As far as I know these algorithms rely on randomness and if their randomness is "guessable" they lose their purpose.

[odolvlobo]

What's the best *deterministic* algorithm/solution (i.e. no Shamir Secret Sharing Scheme) to turn a secret into 6 shards—with any 2 of these shards rebuilding the secret?

Please forgive my ignorance, but what's wrong with SSS and what do you mean by "*deterministic*"?

I believe he means the output is always same. AFAIK some SSS tool (such as https://iancoleman.io/shamir/) would generate different output if you use exactly same input on different occasion.

Then the solution is simply to use non-random inputs, though as pooya87 pointed out, that would introduce weaknesses.