Week9 - Algebra, RSA #
This week we recap the basics of algebra. Then we take a deep dive into RSA encryption. Lastly, we introduce rings and do some practice exercises.
Resources #
This week the exercises and everything related to the topic are on the slides.
Notes on Last Exercise Sheet #
- Overall the exercises were very good this week (:
- You cannot start with what you want to prove! If you do, you arrows have to be reversed (go from bottom to top).
Whenever you define a function (the inverse is a function!), you need to check if it is well-defined. This means that if you base your function definition on a specific representation of an object (for example on $a$) for the equivalence class $[a]$ then you have to prove that for any representation you choose, you get the same result. I.e. $f([a]) = f([b])$ should hold if $[a] = [b]$.
Exercise Sheet Recommendations #
The three-start exercises are probably not that relevant (for passing the exam), so skip them if you don’t have the time. Otherwise all exercises seem fun. 9.7.1 is very good to practice!