Hi
Data recovery is not just limited to LibreOffice. But LO has some neat features that are a great help although usually they might be a pain.
Every time i open LibreOffice it asks if i want to recover the last item(s) i was working on. If i let it try then it's not always successful but when it is it sometimes gives me a version that has the extra edits made since the last save. There is the "Backups" folder in the User Profile.
On the Users List we have helped people recover corrupted documents by
1. make a copy of the file
2. rename the file-ending from .odt to .zip (also works with docX but not doc but it doesn't make up for any of the other problems with docX)
3. Double-click opens the file as an archive file with a few text-files and some folders
4. The "contents.xml" file can be copied into a new file. The "images" folder might contain some 'lost' images
For more general data-recovery it's often worth hunting around emails for a fairly recent but earlier version. Check usb-sticks. A fairly recent version might be on a phone, perhaps in a temp folder or on another computer you might have used recently.
Chances are that if you can get a fairly recent version then re-doing recent work just takes a fraction of the time. A couple of hours work might be re-created in under 10mins because as you bump into the same problems you magically remember the decision you took at the time instead of having to ponder all over again. Most of the times you changed your mind or reworded better or corrected mistakes you will find you magically go the right way first time this time or even improve on it further.
For proper data-recovery you need to stop using the machine and take some time to figure out how to do the least number of writes possible to the hard-dive and make a copy of the hard-drive so that whoever is going to do the data-recovery can work on the copy. If the machine is already off you might be best off using a LiveCd or LiveUsb to avoid "mounting" the problem-drive
https://help.ubuntu.com/community/DataRecovery
In general anything like password protecting a file or encrypting a folder or hard-drive is far, far more likely to result in losing data than in preventing anyone from accessing the data.
For most people shared passwords have to be
1. So easy that a moron could crack it within half an hour or a determined cracker in under a minute. Most times a password is used just try typing in "password" and chances are that will get you in. (for bank and credit cards try these 3 numbers for a 25% chance of getting in 1234, 1111, 2222 (btw if your number is any of those 3 then change it asap, perhaps use the letters under the keys to make a useful word, for example b a n k = 2 2 6 5 on almost any keypad but amazingly that number is not even in the top 20! Choose a better word, obviously!))
2. Impossible to remember and impossible to pass on even if you do remember so the file is never opened ever again by anyone including yourself
The middle ground between those 2 states is precariously tiny. Better to avoid password protection whenever possible and fingerprint scanners are even worse.
Regards from
Tom