For this week, I have been assigned a new room at TryHackMe:

Encryption - Crypto 101

Let's get into it!

We start with a list of terms. Always a good policy to define terms early.

The next topic was the importance of cryptography as well as its ubiquity.

Following that was Crucial Crypto Maths. They discussed the modulo operator, which I first learned about in a codecademy module. I remember thinking that's cool, but I can't even conceive of a way to use it. Lucky for us, cryptographers did. I had to break out the terminal and run a python to get through the questions. Fun stuff.

Next subject was Types of Encryption, which covered material from one of my textbooks, and required a little light web searching to pass the questions and the end of the section. The main subject was Symmetric vs Asymmetric encryption.

After that I finally learned what RSA stands for. Two of my family members have been working with the RSA conference in San Fransisco for years. It's nice to learn a bit about where it's namesake comes from. So, the heart of RSA is that it is difficult to work out what two prime numbers were multiplied together to form a large number.

The next topic was Establishing Keys Using Asymmetric Cryptography. This covered the concept of asymmetric encryption. I wish I could say I understood it perfectly after reading this (and one of my textbooks), but I still feel a little unclear.

So here is what I do understand:

Alice uses her private key plus the public key to encrypt the data.

The data is sent in its encrypted state.

Bob uses his private key plus the public key to decrypt the data.

What I can't seem to comprehend is how the data is decrypted without Alice's private key, or alternatively, how does Bob's private key decrypt the public key? 

Okay. Several youtube videos later, I think I'm making progress:

Alice uses Bobs public key to encrypt the data.

The data is sent in its encrypted state.

Bob uses his private key to decrypt the public key and retrieve the data.

Hopefully I comprehend this at this point. One of the most challenging things to do is to explain a complex problem simply while still being sufficiently explicit. I'm getting flashbacks to the countless half-ass explanations of recursion I slogged through.

Next task was Digital signatures and Certificates, which had a question that required me to make a couple clicks on my web browser to find the answer to.

Okay. Real talk. I found the instructions in the next room about SSH to be pretty poorly presented. After messing around for much longer than I had hoped, I moved on. I will update with a supplemental blog entry when I re-visit this. It's an interesting topic, but a time consuming one.

Next came Explaining Diffie Hellman Key Exchange. They linked to this brilliant video: https://youtu.be/NmM9HA2MQGI

Really cool stuff.

Then they covered PGP, GPG and AES. This looks like a lot of fun, but I'm running out of time today, and I still have more homework to do. I will add this to my supplemental post.

Finally, the discussion turned to The Future - Quantum Computers and Encryption. The power of quantum computers will make cryptography difficult in the near future.