SECURITY SYSTEM, ENCRYPTION DEVICE, DECRYPTION DEVICE, RE-ENCRYPTION DEVICE, OBFUSCATION DEVICE, METHOD THEREOF, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a re-encryption method having an inner product predicate encryption function.;SOLUTION: A method includes the steps of: generating W'=W(0,1)*(h(1)^a(1))^r', Θ'=Θ(0,1)*(h(1)^b(1))^s', Y'=Y(0,1)*h(1)^r'+s', U'=U(0,1)+(REV^→)_B(1), Λ'=Λ(0,1)*h(1)^ζ', Ψ₁=e₁(W',Z₁), Ψ₂=e₁(Θ',Z₂), Ψ₃=e₁(Y',Z₃), Ω₁=e_n+μ(U',k^*) and Ω₂=e₁(Λ',k₀), from an encrypted text ct (0,1) including W(0,1)=(h(1)^a(1))^r, Θ(0,1)=(h(1)^b(1))^s, Y(0,1)=h(1)^r+s*m, U(0,1)=(CV^→)_B(1) and Λ(0,1)=h(1)^ζ; and generating a re-encrypted text ct (1,2) including E(1,2)=Ψ₁^y, F(1,2)=Ψ₂^y, G(1,2)=Ψ₃^y*Ω₁^y', Z(1,2)=Z₃^y and H(1,2)=Ω₂^y'.;COPYRIGHT: (C)2013,JPO&INPIT