Just learning a new language, so the requirement is self-imposed. But the fun thing with RC4 key schedule is that it doesn't have to be provided, one can just implement it based on the Wikipedia code. I have long found RC4 exciting to implement when trying out new languages - I get a quick dopamine hit because I implemented something... real, and it has several other uses besides encryption - especially when just toying. Today I learned I can use it to shuffle arrays.
