[Twisted-Python] Securing a custom protocol

[Brian Granger]

Hi,

I have written a custom line based protocol using twisted.  I need to  
add authentication and encryption to my protocol and I am wondering  
what the best route is.  Here are some options that I see:

1.  Use SSL for encryption and cred for user authentication

2.  Use SSH through conch

As I understand it, both of these approaches can do authentication  
and encryption of any protocol.  What are the advantages and  
disadvantages or each?  Which is more robust and supported in  
twisted?  Are there other approaches in twisted that I am missing?

Some design constraints I have:

1.  I need the protocol to be as fast as possible - low latency and  
high throughput.

2.  I need to be able to run the protocol without encryption when  
speed is more important than security.

Thanks!

Brian