| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and device for giving a signature in a digital form to a message. <P>SOLUTION: A signature system is provided, in which a message is divided into: a first part that is an invisible part where a message is restored during authentication; and a second part that is a visible part necessary as an input to an authentication algorithm. A first signature component is generated by ciphering only the first part. An intermediate component is generated by combining the first component with the visible part and hashing the combination cryptographically. Next, a second signature component is generated by using the intermediate component, and this signature is provided with first and second components having visible parts. The signature authentication combines the first component obtained only from the invisible part of the message with the visible part; and generates a hash of this combination. To generate a bit string relating to the invisible part, the calculated hash is used together with information opened to public. When necessary redundancy exists, the signature is approved, and the message is reconstructed from the restored bit string and the visible part. <P>COPYRIGHT: (C)2011,JPO&INPIT |
