Reply To: Extracurricular challenges

[the_cryptographer_formerly_known_as_madness]

@upsidedown,

It turns out that what was true yesterday is no longer true today. How this could possibly be is a question to ask my pet mice. But as for today, you are correct.

@others,
The secret to solving Hill + Vigenère ciphers quickly is that you only have to do one row of the inverse matrix at a time.