QUOTE (Tymeaus Jalynsfein @ Aug 22 2010, 04:37 PM)

The problem is that you will not be able to use the connected device (Whatever it may be) until the Encryption is completed, and if you re-encrypt it each Turn, you have effectively rendered the device useless...

How do you mean?
Suppose Node A and Node B have a connection they wish to secure. A spends a simple action in Turn1IP1 to engage Encryption using Key 1. I'm not aware of any rules that say B needs to spend any actions to continue using the connection.
Now on Turn2IP1, A just uses the Encrypt simple action again on the same connection, so that A and B are now using Key 2 to communicate.
Any attempts by C to crack Key 1 are now worthless, since Key 1 isn't being used anymore. But since any check to crack Key 1 takes a whole turn, it's unlikely C cracked Key 1 in time to get any use out of it.
What does this cost A and B? A simple action every turn by A, and it an encrypted connection eats up a Subscription slot (#ystemx2 available) and a program slot (#System available). That's really pretty cheap for an encryption you can't hack in time to gain real-time access.
It gets even nastier if you try to secure your commlink; simply have an agent in your node use R6 Encrypt every turn at IP 1. The only way people can hack your node is if they fulfill all the below:
- Get 12+ hits on Electronic Warfare+Decrypt in Turn T=-1
- Win initiative in Turn T = 0 against your R6 agent (who can profit from your Response Enhancer to have an Initiative of Rating+Response+Response Enhancer = 15)
- Brute-Force hack your node in a single Complex Action
At this point, and only then, you get to wonder what happens to people in a node that
becomes encrypted if those people don't know the encryption key.