METHOD FOR GENERATING, ENCRYPTING, AND DECRYPTING PUBLIC KEY AND CRYPTOGRAPHIC KEY ON BASIS OF MODULE-WAVY AND MODULE-LWR

According to the present invention, a method for generating a public key and a secret key, performed by a computer, comprises: a first step of determining a secret key (s) by sampling at an arbitrary distribution on {-1, 0, 1}nd; a second step of determining a first error vector (e) by sampling at (Dαqn)d and determining a second error value (e') by sampling at Dαqn; a third step of selecting a randomly uniform matrix A satisfying A·s = e(mod q); a fourth step of selecting a random column vector b satisfying = (rounded value of q/2) + e'(mod q); and a fourth step of determining the public key (pk) as ( A∥b ) ∈ Rqd×(d+1).