BLOCK ENCODING METHOD AND BLOCK ENCODING/DECODING CIRCUIT

摘要

A block encoding method capable of eliminating overhead of key scheduling, significantly reducing the time required for encoding or decoding, and increasing the speed as a whole. The method uses a key scheduling circuit (12) for forming round key data from key data for encoding or decoding and a bank memory (13) for storing the round key data formed by the key scheduling circuit (12) in a predetermined bank. The method further uses an encoding/decoding circuit (11) for receiving the round key data stored in the bank and plain text data or encrypted data block by block and executing encryption or decryption of the plain text data or encrypted data. The result of the encryption or the decryption is acquired from the encryption/decryption circuit (11).