python: how to encrypt a file?

Question

Can anybody help(or point to some examples) about how to encrypt files with python? I have to use following parameters to encrypt file:

block size=8
iv=qwertyui1         


        

Answer 1

IV stands for Initialization Vector. Block cipher algorithms can be used in several operational modes; one of these modes is called CBC (Cipher-Block Chaining), in this mode the plain text block is XORed with the encrypted previous block. The IV is XORed with the initial plain text block. The IV can be see as an algorithm parameter.

A more detailed description can be read here.

Answer 2

Use pycrypto - note that implmenting crypto properly, even using a library for the hard parts, is tricky. If security matters get expert help.

Answer 3

You will need to use the Python Crypto Toolkit

IV is the Initialisation Vector.