True, having sufficient duplicate chunks to dedupe an encrypted file isn't reassuring. But, Joe was just using the same DB and backing it up multiple times with no activity.

I would think that in a "real-world" situation, the space savings would be less with encrypted backups. You'd still get some, simply because the odds are that there will be duplicate chunks, even if the chunks are for completely different parts of a file or completely different files.

After all, if you've got two files, lets say one a Word document and one an SQL backup file, and they both contain a duplicate sequence, deduplication could work with that.

Jason