A share recovery system including n share recovery apparatuses p 0,..., p n-1, in which n ≥ 2k-1, m ≤ n-k, i is an integer equal to or greater than 0 and less than k, j is an integer equal to or greater than k+1 and less than k+m, [a] 0,..., [a] n-1 are shares obtained by dividing information a into n pieces through Shamir's secret sharing, σ 0,..., σ k-1 are k share recovery apparatuses holding valid shares [a] 0,..., [a] k-1, and τ k,..., τ k+m-1 are m share recovery apparatuses holding invalid shares [a] k,..., [a] k+m-1, the share recovery apparatus σ i (1, 3) includes: a random number generating part configured to generate a share [r] i of a secretly shared value [r] shared through Shamir's secret sharing, which becomes a random number r when restored; and a concealing part configured to calculate a share [b] i of a secretly shared value [b] shared through Shamir's secret sharing, which becomes a value b when restored by subtracting the share [r] i from the share [a] i, the share recovery apparatus τ k (1, 3) includes: a random number generating part configured to generate a share [r] k of the secretly shared value [r] shared through Shamir's secret sharing; a share communication part configured to receive shares [b] 0,..., [b] k-1 of the secretly shared value [b] shared through Shamir's secret sharing from the share recovery apparatuses σ 0,..., σ k-1; a recovery part configured to recover shares [b] k,..., [b] k+m-1 of the secretly shared value [b] shared through Shamir's secret sharing using the shares [b] 0,..., [b] k-1; and a restoring part configured to calculate the share [a] k by adding the share [r] k to the share [b] k, and the share recovery apparatus τ j (1, 3) includes: a random number generating part configured to generate a share [r] j of the secretly shared value [r] shared through Shamir's secret sharing; a share communication part configured to receive a share [b] j of the secretly shared value [b] shared through Shamir's secret sharing from the share recovery apparatus τ k (1, 3); and a restoring part configured to calculate the share [a] j by adding the share [r] j to the share [b] j. a random number generating part configured to generate a share [r] i of a secretly shared value [r] shared through Shamir's secret sharing, which becomes a random number r when restored; and a concealing part configured to calculate a share [b] i of a secretly shared value [b] shared through Shamir's secret sharing, which becomes a value b when restored by subtracting the share [r] i from the share [a] i, the share recovery apparatus τ k (1, 3) includes: a random number generating part configured to generate a share [r] k of the secretly shared value [r] shared through Shamir's secret sharing; a share communication part configured to receive shares [b] 0,..., [b] k-1 of the secretly shared value [b] shared through Shamir's secret sharing from the share recovery apparatuses σ 0,..., σ k-1; a recovery part configured to recover shares [b] k,..., [b] k+m-1 of the secretly shared value [b] shared through Shamir's secret sharing using the shares [b] 0,..., [b] k-1; and a restoring part configured to calculate the share [a] k by adding the share [r] k to the share [b] k, and a random number generating part configured to generate a share [r] k of the secretly shared value [r] shared through Shamir's secret sharing; a share communication part configured to receive shares [b] 0,..., [b] k-1 of the secretly shared value [b] shared through Shamir's secret sharing from the share recovery apparatuses σ 0,..., σ k-1; a recovery part configured to recover shares [b] k,..., [b] k+m-1 of the secretly shared value [b] shared through Shamir's secret sharing using the shares [b] 0,..., [b] k-1; and a restoring part configured to calculate the share [a] k by adding the share [r] k to the share [b] k, and the share recovery apparatus τ j (1, 3) includes: a random number generating part configured to generate a share [r] j of the secretly shared value [r] shared through Shamir's secret sharing; a share communication part configured to receive a share [b] j of the secretly shared value [b] shared through Shamir's secret sharing from the share recovery apparatus τ k (1, 3); and a restoring part configured to calculate the share [a] j by adding the share [r] j to the share [b] j. a random number generating part configured to generate a share [r] j of the secretly shared value [r] shared through Shamir's secret sharing; a share communication part configured to receive a share [b] j of the secretly shared value [b] shared through Shamir's secret sharing from the share recovery apparatus τ k (1, 3); and a restoring part configured to calculate the share [a] j by adding the share [r] j to the share [b] j.