| 摘要 |
The digital file management system and method of the present invention provides a processing service that may be located remotely on a computer network that receives digital files from users and performs file identification, authentication and verification, including time, digital signature, and image marking. The system and method may include the remote processing and storage of file information such that the user does not need to maintain any application specific software at the user's local site. The system and method may record additional independent data with each stored image including: a "true date" gleaned from a secure clock which is not settable by the user (the Authentidate(TM)); a number derived from a cyclic redundancy code (CRC) algorithm against the image data; (the "image CRC"); and a CRC derived from the "true date", (the "date CRC"). This additional data may be recorded within each digital file as soon as possible after the file is acquired. If the file is altered after the recording of the additional data, recalculation of the image CRC on the altered file will not match the original image CRC recorded within it. Thus, that the file was altered can be detected. Likewise, if the true date is altered in any way, recalculation of the date CRC will similarly reveal this fact. The image and date CRCs can be checked and verified at any time. If the recalculated value matches the recorded value, the image can be verified as being recorded on the specified date and has not been altered since that time.
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