Crypto edits

Advanced/Cryptography/parts/challenge.tex

@@ -182,5 +182,6 @@ $\gcd(ac + b, a) = \gcd(a, b)$ \par
 [Note on \ref{eua_runtime}] This proof can be used to show that the Euclidean
 algorithm finishes in logarithmic time, and it is the first practical application
 of the Fibonacci numbers. If you have finished all challenge problems,
-finish the proof: show that the Euclidean algorithm runs in $O(\log{n})$
+finish the proof: find how many steps the Euclidean algorithm needs to arrive at
+a solution for a given $a$ and $b$.
 \pagebreak