This is my first real puzzle, so I hope you enjoy it! Sorry if the writing is a little poor, etc..
You are the unstoppable Detective Joshua Brown, and no puzzle can stand in your way!
You awake at once to a phone call from the police: Your best friend since childhood, Doctor Frank Andrews, has been reported missing! Arriving on the crime scene, you search high and low for a clue, when suddenly, you find it.
A handwritten note, taped to the bottom of the mahogany desk in his study. It's not Frank's handwriting. You read it:
"If you wish to see him again, you must prove yourself worthy. The clue to finding Doctor Andrews is hidden behind a painting in this room. Attempting to open the wrong painting will set off an alarm and notify us. We will kill him immediately.".
You shiver in fear: these men clearly mean business. Alongside this note are two more. The first reads:
And the second:
Spurred on by the need to save your friend, you get to work on the case. Frank is an art lover, so there are five replicas of famous paintings on the wall: The Mona Lisa, Basket of Fruit, Sunflowers, The Persistence of Memory and The Scream, but which holds the oh-so-important clue?
Well, that's all. Try to figure out the painting using the three notes, and give a reason with your answer. Good luck!
After this puzzle is solved, I will put up the next part in the series within a few days.
While the first passage appears to be Base64, it's actually not. With that said, you shouldn't just be guessing blindly as to how to decode it. The answer is hidden there somewhere.
The first passage should be decoded first. To decode the second, you require the plaintext from the first.
Apologies for the skewed difficulty, here's one more hint: There is a text string hidden inside the first string. It points towards a common cipher that can then be used to decrypt the first string
The story was shortened after a tip from Travis Kindred (Thanks!)