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+Subject: Re: [Bitcoin-development] Presenting a BIP for Shamir's Secret

+ Sharing of Bitcoin private keys

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+

+On 03/29/2014 01:19 PM, Matt Whitlock wrote:

+> I intentionally omitted the parameter M (minimum subset size) from the shares because including it would give an adversary a vital piece of information. Likewise, including any kind of information that would allow a determination of whether the secret has been correctly reconstituted would give an adversary too much information. Failing silently when given incorrect shares or an insufficient number of shares is intentional.

+

+I do not believe this is a good tradeoff. It's basically obfuscation of

+something that is already considered secure at the expense of

+usability. It's much more important to me that the user understands

+what is in their hands (or their family members after they get hit by a

+bus), than to obfuscate the parameters of the secret sharing to provide

+a tiny disadvantage to an adversary who gets ahold of one.

+

+The fact that it fails silently is really all downside, not a benefit.

+If I have enough fragments, I can reconstruct the seed and see that it

+produces addresses with money. If not, I know I need more fragments.

+I'm much more concerned about my family having all the info they need to

+recover the money, than an attacker knowing that he needs two more

+fragments instead of which are well-secured anyway.

+

+

+

+