BLOCK ENCODING/DECODING METHOD, CIRCUIT, AND DEVICE

摘要

The present invention includes a plaintext memory 11 and an encryption/decryption circuit 13 for encrypting or decrypting original data in blocks. The original data is transferred to the plaintext memory 11 from the exterior. The transferred original data is supplied to the encryption/decryption circuit 13 and is subjected to encryption or decryption in blocks. The result data is substituted for the original data in the plaintext memory 11. When all transferred original data is substituted, the result data is externally output. Therefore, a variable-length block encryption circuit having a simplified structure and reducing the load on a host computer is achieved.