Is there any good external HDD encryption software?

Truecrypt... again

Been using for about a year now, good software, nice and free. (Gods bless open source)

Only downside (I found) is that you will not be able to encrypt the whole drive, only a 'container' on it. That is unless you have another 750GB drive that you can copy all your data onto, encrypt the first drive, then copy it all back into the container. Oh, and encrypting 750GB will take a considerable portion of your day (not that it really matters, but is worth bearing in mind before you start).

I Fourth TrueCrypt

Absolutely amazing software. It lets you create a file that when run through TrueCrypt mounts as another drive. I have used it to encrypt an entire drive before (the formatting does take forever, and I did it before putting data on it, but its well worth it. It will wipe out the entire drive so you need to get the information off of it first, but it's well worth it.) If you choose to encrypt the drive vs just a container (original file type I mentioned), then I suggest you encrypt a partition rather than the entire drive, for it doesn't encrypt the Boot Sector and thus has less of a chance of problems due to data corruption. More than mention, I think this is the ONLY way to go IMHO. You create a very small partition on the drive (as small as you can) and don't format it, then create another partition for the rest and encrypt that partition (again no need to format initially). If you are really worried about security, shred the drive first. In Windows you can then just remove the drive letter from the first small partition so it doesn't try to mount.

The software is great and easy to use on a basic level---I did my first container in minutes from hearing about the program to using it the first time (probably a worthwhile way to learn at first). However, TrueCrypt is also quite powerful, so I'd suggest before doing your whole drive to read as much about it as you can and better understand the features and how to use it.

I have used it on external HDDs, I keep 3/4 of my 2GB flash drive encrypted with it for all of my real documents and PortableApps start menu/programs (the other 500mb is for non-crucial docs that others may need to access readily or I just need to transfer), as well as on my laptop for certain files I want to protect. I've been meaning to encrypt my entire laptop, but just haven't gotten to doing that yet. In all of these cases (flash drive being best example as its on my keychain) I have no fear if I lose it--I can store documents, my FF passwords, e-mails etc, and no one can get into it. Its the type of encryption that if police/FBI/etc encounter, they try some common passwords, but its useless to attempt to crack unless its of major importance.

Hope this was helpful! Good luck with it! Sorry for the length, but the program deserves it.

Plausible Deniability

"Its the type of encryption that if police/FBI/etc encounter, they try some common passwords, but its useless to attempt to crack unless its of major importance."

Such as a prosecution under the CJA.

But luckily TrueCrypt comes with the plausible deniability fucntion which, as yet, I have not explored but have been reliably informed is very good. It works by creating a visible encrypted container (to which it is 'safe' to release the key to an adversary) and can contain some fake files (eg a spreadsheet named 'bank details' filled with crap) but also a second layer of encryption which is not visible (not 100% sure how that works yet, not currently storing anything I need to be plausibly denaiable about) and contains the actual files you wish to keep safe.

Thanks....

So, Truecrypt it is.

Thanks Everyone.

P.