Patent ID: 11888973
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 7:
8. A secure joining method,
where 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 value; r∈Fkm is a vector of a key of a first table; d∈Fvm is a vector of an attribute of the first table; there is no overlap of keys in the first table; and x∈Fkn is a vector of a key of a second table,
the secure joining method comprising:
without reconstructing shares:
using, by a plurality of secure computing apparatuses cooperating with each other, a share [r] of a vector r, a share [x] of a vector x, a share [d] of a vector d, and the u to calculate a share [y] of a vector y which is output when strong mapping that maps a value of each element of the vector r to a value of a corresponding element of the vector d and maps a value that does not exist in the elements of the vector r to the u is applied to the vector x, where the elements of the vector r are a domain of definition and the elements of the vector d are a range; and
using, by the plurality of secure computing apparatuses cooperating with each other, the share [y] to generate a modified second table by joining the second table and the vector y.