encryption (passwords)

[Gerhard Häring]

Gumuz wrote:
> I am quite a newbie regarding encryption stuff. There are some issues
> boggling my head and I suppose these come from the fact that I have no
> clue how to apply encryption in a real-life situation.
> 
> I am using network-sockets to communicate between two(or more) python
> applications. I want to encrypt these messages, or at least a part of it
> e.g. password and such.

Ok. I'd recommend to use SSL instead of inventing your own crypo layer. I'd
probably go with PyOpenSSL.

> My limited understanding of encryption tells me that I need a 'key' to
> decrypt stuff.

There are two kinds of encryption:
- symmetric encryption
- assymemtric encryption

Symmetric works by both ends having the same key. The sender encrypts the
message with the key, the receiver decrypts it using the same key. The
problem is that you have to distribute the keys first, and have a secure
way of distributing the keys.

Asymmetric encryption works by splitting the key up into a private and a
public key. The private key can only be used for decrypting, the public key
only for encrypting messages.

-- Gerhard