Encryption, CyberSecurity, and Number Theory

Cyber security is front and center in the minds of everyone these days.  The DNC got hacked due to lax procedures but plenty of other organizations have been hacked as well.  Once your computer is hooked up to the internet, there is a chance of it being hacked.

Brilliant is a company I invested in back in 2009.  They have a series on Encryption.  Not only do they have a series of problems to help people understand encryption, but they have created an entire wiki around it so people can really understand it.  If you can’t figure out the answer to the problem, there is an entire social network devoted to helping you learn how to solve it.

Here is an excerpt from the Wiki on encryption:

Suppose Alice is trying to send a message to Bob, without Eve knowing what the message is. Unfortunately for Alice, Eve can hear and see everything that Alice says or sends. The goal of encryption in general is for Alice to be able to send the message successfully without Eve being able to determine what the message is.

There are a number of approaches that Alice can use. One of the simplest is to simply write the message down, place it somewhere that only Bob has access to (e.g. Bob’s house), and simply wait for Bob to access the message. This forms the basic principle behind public-key cryptography: only the intended recipient should be able to “unlock” the message, given that the message was encrypted using the corresponding public key (in this case, the public key is the address of Bob’s house).

In practice, this approach has a number of issues, the most obvious of which being that it is impractical to physically travel to a mutually accessible site every time a message needs to be transmitted. Additionally, if the message is stolen at any point during the journey, Eve will be able to determine the message (by simply reading it). Still, the analogy provides some use, particularly since it extends well into the following example:

Brilliant is being used by teachers in classrooms all around the world.  It’s also being used by people like me to have fun, problem solve and keep my math skills sharper than they would be.