公开(公告)号：US10009170B2

公开(公告)日：2018-06-26

申请号：US14810705

申请日：2015-07-28

Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE

Inventor： Jung Keun Lee ,  Bonwook Koo ,  Dongyoung Roh ,  Woo-Hwan Kim ,  Daesung Kwon

IPC: H04L9/06 ,  H04L9/08

CPC classification number: H04L9/0625 ,  H04L9/0861 ,  H04L2209/24

Abstract: An apparatus and method for providing a Feistel-based variable length block cipher, which are configured to, when plaintext having a certain bit length is encrypted, generate ciphertext having the same bit length as plaintext, and to decrypt ciphertext into plaintext having the same bit length. The apparatus includes an encryption/decryption key generation unit for generating a number of encryption/decryption keys corresponding to a preset number of rounds, based on a secret key, the length of the secret key, the length of plaintext, and a round constant; an encryption/decryption tweak generation unit for generating an encryption/decryption tweak based on a tweak, a length of tweak, and the length of plaintext; and a ciphertext output unit for outputting ciphertext having length identical to that of plaintext, based on plaintext, the length of the plaintext, the length of the secret key, the encryption/decryption keys, and the encryption/decryption tweak.

公开(公告)号：US09843442B2

公开(公告)日：2017-12-12

申请号：US14741511

申请日：2015-06-17

Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE

Inventor： Deukjo Hong ,  Jung Keun Lee ,  Woo-Hwan Kim ,  Daesung Kwon

IPC: H04L29/06 ,  H04L9/06

CPC classification number: H04L9/0643 ,  H04L2209/30 ,  H04L2209/38

Abstract: An operation apparatus includes a message expansion unit, a state data initiation unit, a state data generation unit, and a chain variable update unit. The message expansion unit generates a plurality of expanded messages using a message. The state data initiation unit generates the initial value of state data using chain variable data. The state data generation unit generates the final value of the state data by iterating a combination function and a step function using the state data and the plurality of expanded messages. The chain variable update unit updates the chain variable data using the state data of the final value.