It depends on which country we are talking about. Here in the United States, there is no mention of "encryption" in Part 97. It only mentions if your intent is to obscure the meaning of the message then it's forbidden.
You'll discover there is a very thin line between compression and encryption. And generally that boils down to public documentation and intentions. For example: there are ways to use SSH with null ciphers. You could also announce your key in the clear.
In the early days of HSMM before ad-hoc Mesh techniques and out of Part 15 space channels, there was a need to keep unlicensed devices from interacting with ham (part 97) ones. They used a published key to achieve this.
It boils down to intent. For example; if you're talking in pig latin on a repeater solely to keep others from knowing what you are talking about with your friend, that my friend is also forbidden and would be the same as this commonly used encryption notion that simply does not exist as a word in our US regulations.
It would be nice in my opinion if Part 97 took a firmer stance on publicly documented techniques. As those help move the hobby forward.
As for Amprnet (ARDC) making some sort of statement on traffic over the internet, I don't feel that is necessary. It's much too complicated with all the various countries involved and should be up to the folks who do interconnect over the air stuff to the internet. Some prefer not having to decapsulate when passing the traffic over RF. If encrypted traffic over the internet is important to you, find like minded folks and coordinate something that does that.
I do think using the LoTW certificates for the Portal login and user verification does make sense from a spam and abuse perspective.
On Fri, Dec 3, 2021 at 1:55 PM Cliff Sojourner via 44Net 44net@mailman.ampr.org wrote:
They are on the same spectrum of methods to remove the entropy of a message. Basic cryptography.
What compression techniques are we presently allowed to use over the air?
Cliff K6CLS CM87