Patent ID: 8817978
Filing Date: 2014-08-26
Classification: H04L

Abstract:
1. An order-preserving encryption apparatus comprising: an initializer for setting a total space of a ciphertext with respect to a total space of a plaintext by considering security of the ciphertext, and setting a secret key for encryption and a pseudo-random number generator for generation of a pivot point; a pivot point generator for applying the secret key to the established pseudo-random number generator to generate a pivot point for the plaintext to be encrypted; a ciphertext generator for generating information about size of a bit constituting the ciphertext by comparing the generated pivot point and the plaintext; and a plaintext adjusting unit for wherein the ciphertext is completed by repeating from said generating the pivot point to said adjusting the plaintext for n times, said generating the pivot point performed after the resulting adjusted total plaintext space is determined from the previous round, where n is the total length of the ciphertext in bits.