Sunday, January 1, 2012

Encrypting Files the Easy Way


Update: Are you a school district administrator? 
Update 05/28/2014 - TrueCrypt is now defunct

You may want to read this article, 5 Encryption Tips for Administrators, as well!

Source: http://cacm.acm.org/system/assets/0000/1801/110909_SafehouseSoftware_Encryption.large.jpg?1257790589&1257790588
Since a close relative may be travelling to college soon, I wanted to make sure she knew how to encrypt/decrypt files. After all, who knows what kind of confidential data she might have to send via email or would have to be sent to her encrypted? But if you're a school or government official, encrypting confidential data you are responsible for is critical, too!

Need help creating passwords? This web page creates random, hard to crack ones!

Wouldn't it be neat to have an easy-to-use, cross-platform (maybe you work on Windows at work, Mac at home?) tool you could use for encrypting files? One way to accomplish this is to take advantage of Advanced Encryption Standard (AES) to encrypt confidential data.
Advanced Encryption Standard (AES) is a specification for the encryption of electronic data. It has been adopted by the U.S. government and is now used worldwide. It supersedes DES.[3] The algorithm described by AES is a symmetric-key algorithm, meaning the same key is used for both encrypting and decrypting the data. (Source: Wikipedia)

I'd heard of "AES" and used it without really doing too much digging, except to see things like the following:
The National Security Agency (NSA) reviewed all the AES finalists, including Rijndael, and stated that all of them were secure enough for U.S. Government non-classified data. In June 2003, the U.S. Government announced that AES may be used to protect classified information 
Source: Wikipedia
I've tried sharing a few solutions, but all proved a bit cumbersome depending on the situation (e.g. Truecrypt would result in too large a file, GPG/PGP involved private/public key encryption, solutions were OS specific). I found myself wishing for an easier solution.

Anyone--especially students, school staff--should be able to protect confidential files--whether it's your digital copies of medical records, grade transcripts with social security numbers, spreadsheets with your home/office budget, etc.

This free, open source solution--AES Crypt--is available for Windows, Mac and Linux, making it a fantastic cross-platform tool to use for newbies (including myself).
AES Crypt is a file encryption software product available on several operating systems that uses the industry standard Advanced Encryption Standard (AES) to easily and securely encrypt files. 
You do not need to be an expert to use AES Crypt, nor do you do not need to understand cryptography. Using a powerful 256-bit encryption algorithm, AES Crypt can safely secure your most sensitive files. Once a file is encrypted, you do not have to worry about a person reading your sensitive information, as an encrypted file is completely useless without the password. It simply cannot be read. 
AES Crypt is the perfect product for anyone who carries sensitive information with them while traveling, uploads sensitive files to servers on the Internet, or wishes to protect sensitive information from being stolen from the home or office. AES Crypt is also the perfect solution for those who wish to backup information and store that data at a bank, in a cloud-based storage service, and any place where sensitive files might be accessible by someone else. 
Below are some instructions--links included--to how to install and use this program. Realizing that many folks use Windows/Mac, you'll want to click on the links to view the whole process in screenshots (very simple). You can see from the Windows screenshots, it's just not that hard to right-click on a file and encrypt/decrypt files/documents with a password.

HOW TO INSTALL AESCRYPT 

ON WINDOWS COMPUTERS
Installing this program is quick and there are easy-to-understand tutorials online:

1) Download the AESCrypt for Windows Program

2) Double-click on the installation file. There's a tutorial to help you.

3) To encrypt files, right-click on the file you want to work with:


Encrypt

4) To decrypt files, right click on the file you want to work with:

Decrypt

Note that you can email encrypted files to others, save them on an external USB drive, etc. You will need to install AESCrypt on the Windows computer before you can decrypt an encrypted file on that particular computer.

Macintosh Installation and Use
Installation on the Mac is not as easy as one might hope and will surely involve some command line (Terminal) work. Here are the steps I followed:

1) Download AESCrypt for Mac. Notice that this is a ready-to-use version of the source code here. I had a bit of trouble with this step (source code make and make install on Mac, and the GUI didn't work), and hope that this other version will be OK with the developers.

2) Copy the downloaded--aescrypt--file to /Users/yourusername/ folder. You can get there by double-clicking on MacHD icon then opening up the Users folder, then clicking on your username folder.

3) Run the TERMINAL program available in your Mac's Applications-->Utilities folder.

4) Navigate to where the file(s) are that you want to encrypt. If it's the Desktop of your Mac, you would type in the words/commands in purple below:

Mac:~ mg$ cd Desktop

You are now ready to encrypt a file. If the file is named "confidential_stuff.zip" then type the following:

Mac:Desktop mg$ ~/./aescrypt -e confidential_stuff.zip

You will be prompted to "Enter password:" Type a password that you will remember in, press ENTER/RETURN on your keyboard.

To verify the password, you'll be asked "Re-Enter password:" so type the password in again. When the encryption process is finished, you will be returned to a prompt like the one shown below.

Mac:Desktop mg$

If you look at your Desktop, you should now see a file with the filename of "confidential_stuff.zip.aes". This is the confidential file that you can now store on another device, and delete the old one.

That's pretty much it!

GNU/Linux Installation and Use
What I like is that I can encrypt files while using Linux, and then send them to someone on Windows/Mac and they can decrypt them without issue.

To install on Linux (Ubuntulinux), download the source files, extract them, then go to the command line (terminal) and cd into the directory with the files.
cd aescrypt*source/
make
make install
You can encrypt files easily in Linux with this command:

Encrypt a Single File:  
aescrypt -e filename.ext 
Encrypt Multiple files at once: 
aescrypt -e *.ext
where filename.ext is the filename (e.g. confidential_data.txt) or *.ext is a list of files (*.txt). This will result in filenames that end with aes (e.g. filename.aes). If you view that file, you will see that it is encrypted.

Note that you will be prompted to enter a passcode to encrypt the file with...pick something worthwhile.

Decrypting files is also straightforward:
aescrypt -d filename.aes
I sure wish I'd known about this a year ago. Sigh.



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Everything posted on Miguel Guhlin's blogs/wikis are his personal opinion and do not necessarily represent the views of his employer(s) or its clients. Read Full Disclosure

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