I have a program I am developing and am currently using
ed25519 to cryptographicaly sign messages. However, even those signatures are longer than I would like (64 bytes + the message).
The messages I am signing are generated from within my system (i.e. I am generating and signing the messages within my program, on different servers/nodes).
What are the implications if instead of encrypting the messages (with any strong cipher), I would limit the overhead of the signature?
The messages currently are 72 bits long (currently to limit collisions of a relatively small number of messages), but I am thinking about increasing that to 104 or so bits, and appending a salt to it (not sure how long is acceptable), and encrypting the salt+message. On the receiving node, I can then decrypt the message, and verify the salt (so it would need to be an acceptable length).
My overall goal is to be able to verify the message is valid, and retrieve the message (does not matter if it's visible or not) with the smallest overhead possible, with both endpoints under my control, but the communication is always stateless and easily modified by a third party.