Project 4: Experiment Questions 1 and 4

[J C]

I just want to clarify the difference between Question 1 and 4 experiments.  

For question 1, we need to try to see if we can find any key that works(well checking to see if there is a hash mismatch)?  We can do this with random keys or brute forcing?  We do assume we know the correct key in question one correct?  We are just checking to see if it is possible to decrypt cipher_buff with another key.

For Question 4, We assume we don't know the key and just brute force to try and see if we can decrypt cipher buff?