Encryption: Protecting Your Data
Only a few years ago, data encryption was relatively unknown to most computer users. Many realized that governments and corporations used this protection, but why did they need it?
Most people only had a desktop computer and connected using a telephone modem. Interactions with the Internet were relatively brief and their computers only left home (or the office) when going to the repair shop.
Portability Increases Risk
Today, most folks are mobile, using laptops as well as smart phones and other devices that often contain a lot of personal information as do the USB drives and thumb drives we used to store and transfer data. All are at greater risk for loss or theft because they are portable.
Data Encryption Moves Mainstream
Windows 7 Ultimate includes BitLocker Drive Encryption and the Encrypting File System. This capability is easily obtained for other Windows versions by installing third-party software.
But how secure is that encryption software?
Snowden Reveals Massive NSA Access
Edward Snowden, a former contractor for the NSA, revealed that NSA has backdoors into virtually all operating systems and commercial encryption software — realtime access into anybody's computer was a reality.
Governments and corporations are using the threat of terrorism to spy on their own citizens without any oversight from independent third parties and changing laws that protect your privacy so they become ineffective. Everything they have is a state secret, but nothing of yours is. It is this morally-bankrupt status that Snowden felt compelled to reveal.
The NSA has turned the fabric of the internet into a vast surveillance platform, but they are not magical. They're limited by the same economic realities as the rest of us, and our best defense is to make surveillance of us as expensive as possible.
— Bruce Schneier
[T]he one top-secret program the NSA desperately did not want us to expose was QUANTUM. This is the NSA's program for what is called packet injection — basically, a technology that allows the agency to hack into computers.
— Data and Goliath: The Hidden Battles to Capture Your Data and Control Your World by Bruce Schneier
The assumptions that only the “good guys” are using these tools is ignorant. We now live in a world where anyone has access to these tools at the cost of both individual privacy and national security.
This has weakened the Internet everywhere as well as the attractiveness of U.S. technology overseas.
Encryption is the Only Defense
The only self defense from all of the above is universal encryption. Universal encryption is difficult and expensive, but unfortunately necessary.
Encryption doesn't just keep our traffic safe from eavesdroppers, it protects us from attack. DNSSEC validation protects DNS from tampering, while SSL armors both email and web traffic.
There are many engineering and logistic difficulties involved in encrypting all traffic on the internet, but its one we must overcome if we are to defend ourselves from the entities that have weaponized the backbone.
— Nicholas Weaver
What Can You Do? Five Recommendations
Don't be fooled that your communications are uninteresting — that only the “bad guys” are targets.
The NSA is spending incredible amounts of money to ensure that it can see into your computer, compromise your network and to record your phone calls, then storing the information for later study.
- Hide in the network. Implement hidden services. Use Tor to anonymize yourself. Yes, the NSA targets Tor users, but it's work for them. The less obvious you are, the safer you are.
- Encrypt your communications. Use TLS. Use IPsec. Again, while it's true that the NSA targets encrypted connections — and it may have explicit exploits against these protocols — you're much better protected than if you communicate in the clear.
- Assume that while your computer can be compromised, it would take work and risk on the part of the NSA — so it probably isn't. If you have something really important, use an air gap. Since I started working with the Snowden documents, I bought a new computer that has never been connected to the internet. If I want to transfer a file, I encrypt the file on the secure computer and walk it over to my internet computer, using a USB stick. To decrypt something, I reverse the process. This might not be bulletproof, but it's pretty good.
- Be suspicious of commercial encryption software, especially from large vendors. My guess is that most encryption products from large US companies have NSA-friendly back doors, and many foreign ones probably do as well. It's prudent to assume that foreign products also have foreign-installed backdoors. Closed-source software is easier for the NSA to backdoor than open-source software. Systems relying on master secrets are vulnerable to the NSA, through either legal or more clandestine means.
- Try to use public-domain encryption that has to be compatible with other implementations. For example, it's harder for the NSA to backdoor TLS than BitLocker, because any vendor's TLS has to be compatible with every other vendor's TLS, while BitLocker only has to be compatible with itself, giving the NSA a lot more freedom to make changes. And because BitLocker is proprietary, it's far less likely those changes will be discovered. Prefer symmetric cryptography over public-key cryptography. Prefer conventional discrete-log-based systems over elliptic-curve systems; the latter have constants that the NSA influences when they can.
I strongly recommend reading the entire article for the context and to understand what Schneier is saying.
There are a number of good encryption solutions. Pretty Good Privacy (now owned by Symantec) was one of the original products.
- Pretty Good Privacy on Wikipedia.
Folder Encryption Solutions
SafeHouse Explorer is a free encryption solution for disks and memory sticks.
- SafeHouse Explorer uses passwords and maximum-strength 256-bit advanced encryption to completely hide and defend your sensitive files, including photos, videos, spreadsheets, databases and just about any other kind of file that you might have.
Cypherix has a number of products including corporate solutions.
- Cryptainer LE a free disk encryption software, creates multiple 25 MB of encrypted and password protected drives/containers.
- Secure IT encrypts all your files and folders. All you need to do is select a file you want to encrypt and assign a password.
- Cryptainer PE protects your data by creating multiple encrypted vaults for all your files and folders using 448-bit strong encryption without changing the way you work.
TrueCrypt was a free open-source disk encryption software for Windows 7/Vista/XP, Mac OS X and Linux.
WARNING: Using TrueCrypt is not secure
The development of TrueCrypt was ended in 5/2014 after Microsoft terminated support of Windows XP. Windows 8/7/Vista and later offer integrated support for encrypted disks and virtual disk images. Such integrated support is also available on other platforms (click here for more information). You should migrate any data encrypted by TrueCrypt to encrypted disks or virtual disk images supported on your platform.
— TrueCrypt site
The TrueCrypt site recommends migrating from TrueCrypt to BitLocker (instructions are provided). Bitlocker is not recommended by Bruce Schneier because it is more likely to have a NSA back door (see recommendation 5).
FreeOTFE is a free, open source, "on-the-fly" transparent disk encryption program for PCs and PDAs that allows you to encrypt the entire drive.
- Supports all versions of Windows from Windows 2000 onwards (including Windows 7).
- No need to install it; making it ideal for use on USB memory drives, etc.
- Highly portable. Not only does FreeOTFE offer portable mode, eliminating the need for it to be installed before use, it also offers FreeOTFE Explorer — a system which allows FreeOTFE volumes to be accessed not only without installing any software, but also on PCs where no administrator rights are available. This makes it ideal for use with USB flash drives, and when visiting Internet Cafês, where PCs are available for use, but only as a standard user.
More About Encryption
These sites have useful information on encryption:
- A Guide to PGP Encryption from Data Recovery Labs.
- Peter Gutmann's Encryption and Security Tutorial.
- Matt Blaze's cryptography resource will give you more insight to this technology and the various issues, including legal issues.
- Old Technopanic in New iBottles looks at arguments for and against “back doors” to encryption software.
Updated: May 15, 2015