Cracking the Nimbus Cipher with Differential Cryptanalysis (PicoCTF ’21 — Clouds)

When did Goku create a cipher with his Nimbus Cloud??!

I tackled this cipher in the “Clouds” problem of PicoCTF ’21 but the solution I present in this writeup applies to the actual Nimbus Cipher. In “Clouds” (PicoCTF ‘21), you’re…