In the age of hacking, what is encryption?

Jonathan Okasinski, For The Knight Crier

Nearly every website and online service has encryption.  It works in the background, protecting you while you lackadaisically drift through yet another page of Instagram photos.  Encryption does this by making your message unreadable to anyone except for you and the person that you send your message to.  But how does encryption work?

 

Let’s consider a simple example.  Alice wants to send Bob an email.  However, there is a malicious eavesdropper, named Eve, who is watching.  So, Bob generates a mathematical function kind of like a lock and key.  Bob keeps the key, and sends Alice the open lock.  Alice writes her message, puts it in a box, closes the lock, and sends it back to Bob.  Since only Bob has the key, Eve cannot open the box to read the message.  In the real world, the locks are complex mathematical functions, but the basic principle is similar.

encryption-sized

Encryption, therefore, allows any two parties on the Internet to communicate securely with one another.  Encryption makes secure online transactions possible; it prevents your messages from being read by third parties; it ensures that hackers cannot add computer viruses to your downloads.  Ever wonder what that little green lock in the upper corner of your browser is?  That’s indicating that your communication is encrypted.

 

Encryption is ubiquitous throughout the Internet.  However, encryption is not bulletproof, and there are many ways to attack it.  Eve could steal Alice’s password, or simply guess Alice’s password by trying every possible combination.  Maybe the lock that Bob sent can also be opened by a “master key,” which Eve has.  The lock itself might bear some clues as to what the password is, making it easier for Eve to guess.  These methods of breaking encryption are called vulnerabilities.  Some vulnerabilities are easily exploited by anyone, whereas other vulnerabilities may require supercomputers to perform massive calculations.

 

These vulnerabilities defeat the point of encryption, as Eve can now use the vulnerability to read Alice and Bob’s secrets.  Occasionally, the organization writing the computer code for encryption will knowingly insert vulnerabilities into encryption, making it weaker.  When this is done, it is known as a backdoor.  Backdoors are similar to a master key that unlocks all the locks.

 

With encryption being so ubiquitous, it is not surprising that it often appears in the news.  Since it has been discussed in the context of everything from government oversight to national security to terrorism, encryption may seem to be difficult to understand.  But next time you read about encryption, it will be less mysterious and much more intriguing.