PoW
+Why is it loading so long?
++ Your browser is calculating something to prevent abuse. The time it takes depends on the + power of your CPU and, believe it or not, luck. Sometimes it takes like 5 seconds, sometimes + 30 secs, so please be patient. If you want to know what's going on, go to the technical part. +
+Technical Part
+
+ The technique used, is called PoW, or Proof of Work. It is a way to "pay" for something by
+ using your CPU. It's mainly used in crypto-stuff, but not in ClassQuiz. It's just used to
+ prevent spam. Imagine it like a small fee you have to pay to upload an image, but you don't
+ pay with money, instead by using your CPU intensively. The Proof of Work-algorythm used is
+ called HashCash and is also used by Bitcoin. All in all, it's really simple (if you know
+ what hashes are). Let me explain:
+
+ You're hashing a string with a counter until the first x characters (in this case 4) are "0"/zeros.
+ That's it. Then, you send the counter to the server, who hashes it once, checks if the first
+ x characters are really "0" and that's it.
+