| 摘要 |
Successive round keys of an expanded key according to the AES block cipher algorithm are generated from an initial cryptographic key, for use in a cryptographic (encryption and/or decryption) engine, in real time as the cryptographic process is executing. A limited key memory is used by overwriting previously generated words of the expanded key, leaving only the words of the initial key and the final key in the memory. Thus, a subsequent cryptographic operation can recommence either in the encryption or decryption direction, without delay to the cryptographic engine. |
