Not updating its timestamp livelink
That kind of timestamp comparison is actually the basis for incremental backups: backup only those things that have changed since the last backup.Truecrypt volumes are container files that, in turn, contain in encrypted form a complete file system along with all the files and folders you choose to place in the Truecrypt volume.If the volume is mounted and you change a file within it - say you edit P:\- you might expect the container file - - to then also have the same timestamp, since that's the time at which it was last modified. By default a Truecrypt container's 'last modified' timestamp is not updated by Truecrypt. At least not until you think about what Truecrypt is trying to do.Truecrypt is trying to keep your encrypted information private.
When dismounted only the container file - in this example - remains visible, and if examined is only so much random data since it's encrypted.
Note: your container may still be dismounted in order to be backed up.
When the container is mounted Truecrypt locks it such that most other applications cannot actually access it.
More specifically, the "last modified" timestamp, which indicates when the file was last changed.
By comparing the file's timestamp with that of its backed up copy, the backup software can infer either that the file hasn't changed since it was last backed up, or that it has and thus the backup needs to be updated.