Super User is a question and answer site for computer enthusiasts and power users. It only takes a minute to sign up.
Sign up to join this community
The deleted files still lurking in the filsystem (that Eraser would delete) will be encrypted as well, as the whole filesystem is encrypted. So it ends up with how secure one thinks it is to encrypt the disk with TrueCrypt. One can only find the deleted files if one can get access to the crypted filesystem (with password or cracking it).
The only way to completely protect data is to destroy all copies of it beyond possibility of recovery. So yes...shred your disks. And if you've memorized any of the data, shred your brain too.
It depends. Using TrueCrypt definitely gives you better security. That's because if someone's looking for your deleted files then s/he have to get your TrueCrypt credentials. Then s/he can decrypt your file system and maybe can get back your deleted data.
Getting your password or the encryption key is not as hard as it seems to be. (Well, if the attacker gets physical access to your computer.) There are hardware and software keyloggers. There's the cold boot attack, just to name a few.
However, shredding your entire encrypted volume is extremely easy. All you have to do is to shred the encryption key. This is usually a few kilobytes. For example, if you want to "destruct" a TrueCrypt volume just shred the first megabyte of the volume and it's very unlikely that someone will ever get any data back from it.
Well, just in case someone beats the password out of you... Or places small spy camera above your keyboard... Maybe it is reasonable.
It all depends on levels of data sensitivity and paranoia, I think.
I will give you the answer from a security professional's perspective.
Hard disk encryption is indeed a good feature and it can keep all but the most savvy users out of your data, however something to note here is that is indeed possible to get in.
One method which has been making some news lately is to cryogenically cool the memory module so that it can be removed and inserted into another machine before the memory zeros out. This gives them access to everything in memory including the encryption key that keeps your data secure.
So the short answer is that file shredding is still needed if you do not want others to potentially have access to the data. Even a fully encrypted hard drive still can be broken by a person with the right skills. Just look at Bruce Schneier. He makes a living as a consultant training people how to protect from these kinds of threats. A cryptanalyst could certainly get in and gain access to the data should they have sufficient motivation and enough computer power to throw at the problem.
Another note on many of these encryption schemes. The only truly secure encryption method is a "One Time Pad"... Everything else generally has a mathematical solution which is how they know when they have cracked the code. A one time pad is not breakable with any amount of processing power because it is not a math problem but a problem of knowledge.
Encrypting does not negate the need for file shredding. There are ways to get around Truecrypt if someone gains physical access to your machine.
shred and link it to donothing or copy instead.
May 2 '12 at 8:42
If the whole volume is encrypted with TrueCrypt, you do not need to shred anything on the volume, period. Read the TrueCrypt documentation.
