A Question The Press Isn’t Asking About Government Surveillance
Would you believe me if I told you that breaking really good encryption requires a lot of energy?
Encryption. The government hates it because it provides real privacy for people who want it. Governments around the world see it as a threat. Personal privacy is an issue that has been in the news with stories about PRISM, a program to allow the biggest social networking sites to share information with the government. The government would like us to know that they’re very earnest in their efforts to protect us from terrorists.
Few people use encryption actively. I say “actively” because many people do use encryption when they visit a secured web page that uses SSL encryption (you’ll know you’re using SSL security when you see https at the beginning of an address in your browser). But emails? Attachments? Encryption for emails is still spotty. Wired Magazine has the following take on the subject of encrypted emails as late as 2014:
Every email we send is insecure by default. While Google and Yahoo have taken positive steps to encrypt traffic, the basic protocols are still all plaintext, and forget about controlling the emails you compose after you hit send. While an email address routes your message to a recipient, there’s no ability to recall or encrypt messages baked into this 30-year-old standard.
Completely secure email is still very hard to find because the Simple Mail Transport Protocol, the one we use now, didn’t contemplate privacy when it was invented. Ensuring privacy in email has been so difficult, that even in the present day, big business is still including disclaimers in their email signatures at the server level. That means that no matter what you use for your signature, the email server appends text to your message that looks substantially like this before the server sends it:
The content of this email is confidential and intended for the recipient specified in message only. It is strictly forbidden to share any part of this message with any third party, without a written consent of the sender. If you received this message by mistake, please reply to this message and follow with its deletion, so that we can ensure such a mistake does not occur in the future.
A good chunk of all email still sails across the internet as clear text because most people don’t know about encryption and how to use it. There are many forms and techniques for encryption. Encryption is the use of a mathematical algorithm to scramble a message so that it cannot be read by others. Only the person with the key can decrypt the message. A very well known encryption method is called Pretty Good Privacy (PGP), invented by Phil Zimmerman in 1991. It is a standard today for personal and industrial encryption. It is also open and free. Anyone can use it. But it is not widely used mostly because it’s not advertised much, and PGP is not the easiest thing in the world to use, either.
So that begs the question: Why didn’t Microsoft make it a standard? My first thought on the question is that Microsoft doesn’t like anything that is free. Microsoft could easily bake PGP into Outlook, but they didn’t want a form of encryption that would work well with Linux or Mac. If you want it for Outlook, you may have to buy it. Google offers a free plug-in, too (this didn’t exist years ago when I first looked into PGP).
I suspect that there is a bigger reason: the government discourages encryption without back doors. PGP is just that. There is no back door anywhere and if there were, an alternative could be made quickly to remove it. That’s what’s so cool about open source, free software: the source code is available for modification should the need arise. Generally, open-source software is free as in freedom, not just free as in beer.
The same question could be asked of Apple. Or any other company that sells email client software. But one look at the free email clients like Thunderbird and Evolution will show that the Free Software movement has been quick to make PGP and option. There are PGP apps for Chrome and Gmail, too.
Some of you are wondering what PGP is. PGP is based on the concept of public-key encryption. To encrypt a message or a file, I first create a key pair. One key is public, I share that with you. The other key is private and I keep that private.
I want you to secure the messages you send to me, so I share my public key with you. You use PGP with that public key to encrypt a message to me and then send it. When I receive it, I can use PGP with my private key to decrypt it. It’s that simple in practice. But underneath is an incredible discovery in mathematics that makes it effective.
Bruce Schneier is a security expert. He’s famous for exposing the security theater that is supposed to make us feel safer at airports. But he’s also a software developer. He’s studied encryption for many years and he’s just one more authority on the topic. I found a fascinating excerpt of his work on StackExchange (scroll down to answer 224) from his book, Applied Cryptography, which describes some very interesting facts about encryption.
Suffice it to say that, even if one wanted to use brute force to break encryption, it is not just a matter of time to use every possible combination to find the right key for an encrypted message. It is also a matter of energy. There is a discrete, finite amount of energy required to record, store and test each bit in a key. In short, using brute force to break a 256-bit encryption key would require an enormous amount of energy. Something like 10⁵¹ ergs. That’s supernova energy.
After a very interesting discussion of the energy requirements to break encryption by testing every possible combination of bits in an encryption key, Schneier says:
These numbers have nothing to do with the technology of the devices; they are the maximums that thermodynamics will allow. And they strongly imply that brute-force attacks against 256-bit keys will be infeasible until computers are built from something other than matter and occupy something other than space.
That’s why the government hates encryption. The laws of thermodynamics place real limits on the computational power available to break encryption.
Again, the question remains, why isn’t encryption standard in every email transmission, every application and every server? Someone doesn’t want it to be a pervasive, standard practice. I wonder who that might be. Hmmm.
Originally published on my blog, The Digital Firehose, Saturday, June 08, 2013. Updated for grammar, clarity and a turn of phrase that comes with another editing pass.