Art decryption is the ability used to find codes in paintings that can be used to unlock a safe hidden behind said painting. The three-digit code to the safe appears at least three times in the painting and, after it is found, the safe can be opened, allowing the user to steal the contents. This kind of security technique is only seen in Sly 3: Honor Among Thieves. While all of the art decryption locks seen are cracked by Bentley, Sly Cooper mentions that his father used to do these often, and even makes a remark suggesting he has done them before himself, albeit slowly.
To decipher a painting, walk close to it and press . Use or the directional buttons to move the magnifying glass around the painting, and to zoom in. Once the code has been found, press to lift the painting to enter the code.