Here’s my code: Here’s the error I get: What am I doing wrong? I’m running Python 3.8.3. Answer The mgfunc parameter (3rd parameter) for the mask generation function is incorrectly specified in the posted code. According to the description of Crypto.Cipher.PKCS1_OAEP.new(): mgfunc (callable) – A mask generation function that accepts two parameters: a string to use as seed, and the