Encryption is probably something you take advantage of every day on the Internet without even knowing you are. It is what keeps many of our most private interactions free from prying eyes and provides security of our digital world.
What many people still don’t appreciate is that the vast major of traffic on the Internet is plain text which can be read by anyone who might be able to capture it. Email traffic has to be unencrypted to allow it to be sent between different email systems. Thus, every time you send and email across the Internet, anyone who has access to that email could read its contents. That is why you always need to consider sending an email like a postcard rather than a letter.
The way that you protect digital information is via the use of open encryption protocols. There are of course many proprietary encryption technologies but unless such protocols are open and available for scrutiny by all they cannot be completely trusted. That is why it is always better to use open cryptographic techniques.
The most familiar example for most people is the little lock they see in their browser when they shop online or use their bank. The presence of the lock indicates that the browser is communicating to the server using the secure web browsing protocol known as https, where the ‘s’ stands for secure.
The https protocol is also known as SSL (secure sockets layer) and relies on well know public key encryption. This basically means that each party in the conversation exchanges a ‘public’ key to the other that allows encrypted of messages to be sent. Such messages can then only be decrypted by a ‘private’ key held by the appropriate receiver. In this way you ensure that only sender and receiver can communicate during their conversation.
How good is encryption? Modern encryption implemented correctly is unbreakable, it is that good. The problem is that it isn’t used on enough of the systems we access on the Internet.