I have recently purchased an ENC28J60 module and started experimenting with ethernet connectivity on my various Arduino boards. As to be expected with the Arduino community there are a good number of resources, on here and the wider web, for support in getting a basic project up and running.
I have mainly been experimenting with sending GET requests to a web server and acting upon the responses, and while there is a great deal of guidance about how to achieve this, none of them seem to contemplate the aspect of secure communications. While this may not be so much of an issue on a private LAN, the very nature of 'Internet of Things' would suggest that this communication will take place over a third party network at some point.
I have spent some time investigating the process of implementing some basic encryption on these communications and have found the availability of such information to be very weak. Methods I have looked into so far are RC4 and XOR, and some of the examples actually work on the local microcontroller, but fail to encrypt/decrypt successfully in the PHP implementations at the server.
Have you implemented any kind of encryption in your microcontroller projects? How successful were they? Do you think there are enough resources for data encryption? Or is there something obvious that I've missed? 
Would love to hear your thoughts and opinions.
Paul
