At the risk of sounding stupid and being laughed at...I must ask this question. What is required to decrypt an encrypted file? Obviously you need the appropriate key to decrypt, but is any other information needed in order to correctly decrypt the content?
Please forgive me as I am just learning cryptography and this is the first time I've had to handle encrypting/decrypting files in a program.
Here is the scenario. I have a Python program that generates a file. This program also needs to encrypt that file and then send it to someone else. I'm using a library called keyczar for my cryptography tools. And I'm encrypting the file using AES-256.
My concern is that the person receiving the file won't be able to correctly decrypt the file because they'll be using their own system to perform the decryption process. What exactly does the person receiving the file need to correctly decrypt the file? Do they only need the AES key? Or do they need to know details about the encryption process such as the header, initialization vector, and signature?