Linux - SecurityThis forum is for all security related questions.
Questions, tips, system compromises, firewalls, etc. are all included here.
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
I have read alot of varying information about the possibility of restoring a file in a journaled (or log based) file system. I really want to cut through the fog and get an asnwer specific to my situation.
I am running a ReiserFS system and would like to do the following to securely delete some files:
1. Use rm to delete all files which we wish to have "destroyed".
2. As root (to ensure the last 5% gets done as well), fill all free space with junk files (random copies of known files).
3. With freespace down to the minimum possible, start shredding files. I have been using "shred -n5 -z FILENAME", as I am not paranoid and simply want a secure delete (after all, you can't defend against a truly determined data recovery and still keep your drive; head shifting and electron microscopes see to that).
4. Repeat for all "junk" files which we desire destroyed.
5. Do not delete any individual file until all files have been treated this way.
6. rm the junk files.
Please let me know what you think. I would appreciate explanations and/or pointers to technical papers...
Speaking of which, this is a great/informative read: Secure Deletion of Data from Magnetic and Solid-State Memory by Peter Gutmann, Department of Computer Science, University of Auckland
I just thought of something.... I don't know enough about Reiser to know the answer, but I really hope that Shred is not just writting the whole junk files over and over again into whatever little free space there may be left on the drive... Any thoughts? Anybody know if this is how Reiser would handle this request?
I guess I'm just worried that there isn't an effective solution...
Yes there is. But, question is do you wan't to get rid of that hard drive. If you do, then shred /dev/hdX until the poor thing dies. If you don't, and want to be secure, use encryption. But use a good one, encfs for example.
As a rule of thumb, sensitive files should never touch the hard drive unencrypted.