| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To perform encryption difficult to be decrypted and to shorten an encryption processing time for the outflow of a log file. <P>SOLUTION: Information 301 recorded in an access log file 18 is automatically decomposed into confidential information 304 and non-confidential information 305 utilizing a partition character 312 of a general URL format. The non-confidential information 304 is recorded in plaintext and the confidential information 305 is encrypted and recorded, so that the amount of data to perform encrypting operation thereon is decreased and acceleration is attained. Furthermore, a key of a common encryption key scheme is generated in access log generation, and the key of the common encryption key scheme is encrypted according to a public key encryption scheme (defined as a first encryption scheme, hereafter). Thus, it becomes difficult to decrypt the encrypted confidential information 304 and even if a nonvolatile storage device such as a hard disk storing the access log file 18 thereon is stolen, the key to be used for decryption is not easily ascertained. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
