Bits and Binary
Binary Basics
I'm going to not make my own stuff here and recommend that you use this tutorial, it is fantastic and SparkFun is a great company.
If you haven't played with binary before work through this tutorial: https://learn.sparkfun.com/tutorials/binary
Once you are done with that you're ready for what comes next. You definitely don't need to memorize binary/ASCII (or any other) conversions, just use a cheatsheet like this one: Character Conversion Cheatsheet.
Remember, you don't need to memorize any of this stuff. If you are at a computer, you have access to the resources you need to just look it up every time.
Base64 Basics
I like this article to get the general understanding of Base64 and the other Bases. There are great Base encoders/decoders on the Cyber Chef site, but also plenty more spread throughout the internet, plus of course you can always do these transforms with Python or any other programming language.
Assignment
- What is ASCII?
- What is the difference between binary and octal?
- How many bits are used for each character in ASCII?
- "01101000 01100101 01101100 01101100 01101111 00100001" is in binary. Convert it back to ASCII. Do it by hand using the chart.
- What makes Base64 64? What if it was Base8?
- Decrypt this using CyberChef: "V2VsbCBjeWJlciBjaGVmIHN1cmUgbWFrZXMgdGhpcyBlYXN5IGRvZXNuJ3QgaXQ="