If you are on a network that can be sniffed, adding SSL encryption 
will not really help a lot unless you buy a commercial certificate and 
have a domain name for your computer. Unless you manually check the 
signature of a self-signed SSL certificate manually (something the 
iPhone's Safari doesn't support), you remain fully vulnerable to man- 
in-the-middle attacks.

HTTPS connections are also considerable slower (due to the setup and 
handshaking needed for encryption) and have a much higher latency than 
plain HTTP connections, which makes HTTPS mostly unsuitable for near- 
real-time remote control purposes.

The solution: avoid usage of public wireless networks and using your 
own, private wireless network instead by setting up your Mac as a WiFi 
base station / access point. You can find pictured step-by-step 
instructions on how to do that in the Remote Buddy FAQ.

Best regards, 
Felix Schwarz