Preface This is a tale of the intersection between thermal physics, cosmology, and a tiny amount of computer science to answer a seemingly innocuous question: “How strong does a password need to be for it to be physically impossible to brute-force, ever?” TLDR at the bottom. Note: this post contains equations. Since none of the equations were long or complex, I decided to just write them out in code blocks instead of using images or MathML the way Wikipedia does. Update: I implemented the ideas ...