0

Three participants Quadratic polynomial, one cheater. The Cheater discloses a false (x,y) pair I need to prove that any one of the truth-telling participants can't tell which of the others is the liar. I do realize that any pair of participants have a linear subspace of possible solutions since they don't know the secret they can't tell if it is a member of their subspace, but I don't think it is a proof just an intuition as to why this claim is true.

Nitzan Ben-Hur
  • 11
  • 1

1 Answers1

1

You could use the fact that having two of three pairs does not reveal any information about the secret (polynomial). Also see the Wikipedia article on Shamir's secret sharing: it provides you with a nice graphical answer to your question.

Mike Edward Moras
  • 18,161
  • 12
  • 87
  • 240
dade
  • 1,323
  • 9
  • 14