| 摘要 |
The digital file management and imaging system and method of the present invention record additional independent data with each stored image including: a "true date" which is 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; this number is called the "image CRC"; and a CRC derived from the "true date", called the "date CRC". This additional data is recorded within each digital file as soon as possible after the file is acquired. If the file is altered in any way 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, the fact that it has been 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, it can be stated that the image presently recorded was recorded on the specified date and has not been altered in any way since then.
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