I would include some knowledge of hexadecimal values. It's a fundamental necessity in my opinion and where I would start, since your intercepting data you need to understand data.
You could start from 0-9: 0 = hex 30; 1 = hex 31, 2 = hex 32, and so forth.
Chars range from:a = 61; A = 41; b = 62; B = 42.
You could start from 0-9: 0 = hex 30; 1 = hex 31, 2 = hex 32, and so forth.
Chars range from:a = 61; A = 41; b = 62; B = 42.