| 摘要 |
<p>A message authentication device, a message authentication method, a message authentication program and a storage medium therefor are provided, so as to realize higher speed processing than an authentication mode of existing block cipher, in combination of block cipher and one of its parts, with theoretical security in accordance with a high efficient preliminary process and with an efficient amount of available memory. The message authentication device includes: input means 100 for inputting a message: padding means 101 for padding the message, setting its length always to a constant of a block length, and outputting the message as a padded message; modified tree hash means 102 for outputting hash values of one block by repeating a process of arranging hash functions with small input/output widths, corresponding to the padded message, generated based on parts of block cipher; adjustment value added encryption means 103 for encrypting the hash values so as to set a tag; and output means 104 for coupling and outputting the tag and the message.</p> |
