Hi,
What did you try to solve the tasks?
We will not provide whole solutions for the tasks.However, if you have specific questions, I will happily answer them.
Note: The tasks themselves (on the platform https://websec.cs.uni-paderborn.de/json-sec/sigenc/) give you a general direction in how you can solve them.E.g., verifier 4 can be solved with "Key Confusion". You can look up what this means in the lecture PDF or video.
CheersSebastian