Over this past week I had the opportunity to put my head down and invest some time in my continuing education. I decided that taking a crypto class would be a no brainer. A cryptography certification would dovetail nicely with my Information Security certificate and it continues to be a timely subject. More importantly I am keenly interested in cryptography, and history has suggested that keeping my attention is the key to any line of study…
What’s in a cryptography class
Cryptography often falls under the purview of information security, with good reason. Cryptography is really a specific subset of information security. It includes topics such as digital privacy, integrity, authentication, and non-repudiation. These crypto security goals are achieved with symmetric and asymmetric cryptography (and hash functions.). While that is a vast over simplification, it is also accurate. I think most civilians would be surprised to learn that the safety of their transactions are fully dependent on prime number theory…
Secure encrypted data transfers these days all use methods that will almost surely be broken. At some point. Secure digital communications work today because some very clever folks created nearly ideal one-way functions. These function can easily calculate in one direction, but are very difficult to impossible to work out in the other direction. Brute force ( checking every pair factor that could be the answer ) works, but with todays computers would often take years or decades to crack your proton mail.
What’s is a cryptology
If you know how a Caesar cipher works, you have a basic idea about cryptology in action. Both the earliest simple cipher and modern cryptology share the goal of preventing third parties (or the public in general) from reading private messages. Obviously the way modern cryptoraphers mix up the info is way better than a=r. However Bob still needs a key to un-encrypt what Alice sent him, just like Ceasar did.
These encryption keys are just as important as the encryption algorithms. One of the most interesting developments has been public-key cryptography based on the algebraic structure of elliptic curves over finite fields. Beyond the algorithms getting better and keys getting bigger, another huge advance was when Diffie-Hellman ( et. all) came up with a way so that Bob and Alice could exchange their keys out in public securely. This English dude explains it well:
I went in hard on this course lol, and I got allot out of it. My consulting, software, and tech-support will all benefit from what I learned over the last few weeks. I took the final and passed as soon as I finished the last lecture, no study, no pause. The lovely Teresa came to check on me because I was sitting down for almost 2 straight hours – that almost never happens!
I am looking for the next course to take in the Information Security / Cryptography class vein. If you know of a good online course that is somewhat advanced ( and reasonably priced ) in this area, please let me know in the comments. I am specifically interested in of Elliptical curves and public key cryptosystems.