Distinct Sector Hashes for Target File Detection

There are many limitations when using file hashes to identify known content. Because changing just a single bit of a file changes its hash, pornographers, malware au-thors, and other miscreants can evade detection simply by changing a comma to a period or appending a few random bytes to a file. Likewise, hash-based identification will not work if sections of the file are damaged or otherwise un-recoverable. This is especially a problem when large video files are deleted and the operating system reuses a few sectors for other purposes: most of the video is still present on the drive, but recovered video segments will not appear in a database of file hashes. SECTOR HASHING We are developing alternative systems for detecting target files in large disk images using cryptographic hashe