About
Below are some problems related to computer security (specifically poorly implemented security). Do Them. You are free to use any language and environment you like to complete them. The problems require familiarity with programming, but not necessarily with applied cryptography or computer security in general. An understanding of how some of the algorithms and tools in the problems work will be of use, so as a starting point you can find some resources to help you begin here. If this topic is new to you, you may want to start with the Tutorial Problems.
Problems
Breaking PDF Passwords
Fast hashes are easy to brute force, let's apply this to an actual scheme
Insecure PRNG
Using a PRNG that isn't proven to be cryptographically secure is a recipe for disaster
Cut and Paste Attack On AES-ECB
Create a valid ciphertext without knowledge of the key using some copypasta.
Salt Alone Won't Save You
Salting password hashes is important, but not enough on it's own