[tzs]

Note that various ham bands have limitations on what types of emissions are allowed. For example some only allow RTTY and data, so no phone or image. And some allow phone or image but no data. Even if the type of information is allowed there might be technical restrictions prohibiting some forms of modulation.

So before using something that was designed depending on some non-ham part of the regulations for its legality, such as part 18 (ISM) in the US, on a ham band I'd want to look into the details and make sure it is not doing something under that part but not allowed under the ham regulations.

[agiacalone]

Also, the ham bands as a whole cannot be used for profit-motives or any financial gain. People often forget this rule. Not to mention the (kind of absurd, IMO) rule against any form of encryption.

[sidewndr46]

Encryption is permitted for remote control of space borne systems.

Repeaters may use any method to limit access and control to authorized users.

[agiacalone]

I forgot about that one use case. But it's not allowed for most practical purposes in the U.S. at least.

[sidewndr46]

almost every single repeater I know of uses this method for remote control. I even remember listening to someone sending long strings of high speed DTMF, presumably to try and brute force control of the repeater. One of the managers said they weren't successful

[userbinator]

However, I don't believe there's a rule against steganography.

[threemux]

In the US, there certainly is. The rule doesn't mention encryption specifically, it just prohibits "encoding for the purpose of obscuring meaning". The intent is what matters not the method.

[DoctorOetker]

would oblivious transfer qualify as OK? if the sender provably doesn't know what's transmitted, will the law rule it a form of obscuring meaning?

[sidewndr46]

You're thinking criminal court standards, like beyond a reasonable doubt for a conviction.

It's a procedural thing. The FCC will tell you did it & tell you the penalties. Your options are zero.

[agiacalone]

Yes, the FCC would (theoretically) just revoke your license to prevent you from doing it again if they so wanted.

[userbinator]

Do they also prohibit sarcasm?