Patent ID: 11886876
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A secure strong mapping computing system comprising:
a plurality of secure computing apparatuses, wherein
Fk and Fv are arbitrary rings; [α] is a share generated by secret sharing of α, with α being an arbitrary vector or permutation; m and n are predetermined integers greater than or equal to 1; u is a predetermined outlier value; r∈Fkm is a predetermined vector with elements different from each other; and d∈Fvm and x∈Fkn are predetermined vectors, and
the plurality of secure computing apparatuses include processing circuitry and are configured to, in cooperation with each other,

use a share [r] of the vector r and a share [x] of the vector x to generate a share [k] of a vector k∈[Fk]2m+n which is generated by joining the vector r, the vector x, and the same vector as the vector r,
use the share [k] to generate a share [σ] of a permutation a for stable sorting of the vector k,
use a share [d] of the vector d and u to generate a share [d′] of a vector d′, which is a vector generated by subtracting u from respective elements of the vector d,
use the share [d′] to generate a share [v] of a vector v∈[Fv]2m+n which is generated by joining the vector d′, a 0-vector with a number of elements of n, and a vector −d′ which is a vector generated by inverting signs of respective elements of the vector d′,
use the share [v] and the share [σ] to generate a share [σ(v)] of a vector σ(v) which is generated by application of the permutation σ to the vector v,
use the share [σ(v)] to generate a share [σ(y)] of a vector σ(y), each element of which is a sum of the u and a sum of elements of the vector σ(v) up to an element corresponding to that element, the elements including the element corresponding to that element,
use the share [σ(y)] and the share [σ] to generate a share [σ−1(σ(y))] of a vector σ−1(σ(y)) which is generated by application of an inverse permutation σ−1 of the permutation σ to the vector σ(y), and
use the share [σ−1(σ(y))] to obtain a share [y] of a vector y which is generated by extracting m+1th to m+nth elements of the vector σ−1(σ(y)),
wherein the share [y] includes identification of outliers.