I'm writing some code that needs to run with as small a footprint as possible, because it's on an embedded device. I want to encrypt its communications. I'm trying to find a good, resource-unintensive cryptosystem to use, but I'm struggling.
My first thought is that it fits here, because it's not about using a cryptosystem. The on-topic page seems to support this:
The rule of thumb, here, being that you should post to crypto.SE if you want to understand the internals, and to security.SE if you want to know what you should do now.
I want to pick a cryptosystem based on internal properties, like how much memory it uses. In my eyes, it fits.
On the other hand, asking for libraries is off-topic, and it seems like a small leap to go from "what crypto library should I use" to "what cryptosystem should I use". Basically the only difference is having to specify a language for the former.
So would such a question be on-topic here?