Encryption on Amateur Radio

The conversation about encryption on the amateur radio bands comes up semi-regularly. The conversation usually goes something like the following:

• “Why isn’t encryption allowed? Privacy should be an expectation!”
• insert lots of discussion about reasons
• “But I want to talk to my friends or browse the internet, and without encryption everyone can eavesdrop!”

And then there’s an impasse. I wrote the following in response to a Reddit post (yeah, I know, I shouldn’t be browsing Reddit, but here we are), and I’m certain that I’ll need to reference it again, so I’m creating a blog post out of it.

Something to consider - FCC Part 97 doesn’t deny encryption, it denies obscuring the meaning of a message.

97.309 -

• b: …a station may transmit a RTTY or data emission using an unspecified digital code…RTTY and data emissions using unspecified digital codes must not be transmitted for the purpose of obscuring the meaning of any communication.

97.311 -

• a: SS emission transmissions by an amateur station are authorized…SS emission transmissions must not be used for the purpose of obscuring the meaning of any communication.

That brings up the question of “why?” I am not a lawyer, but let’s see if we can use context clues from P97 to answer.

Starting with the purpose/mandate of the Amateur Radio service:

97.1 - …an amateur radio service having a fundamental purpose as expressed in the following principles

• a: Recognition and enhancement of the value of the amateur service to the public as a voluntary noncommercial communication service, particularly with respect to providing emergency communications.

• b: Continuation and extension of the amateur’s proven ability to contribute to the advancement of the radio art

• c: Encouragement and improvement of the amateur service through rules which provide for advancing skills in both the communication and technical phases of the art.

• d: Expansion of the existing reservoir within the amateur radio service of trained operators, technicians, and electronics experts.

• e: Continuation and extension of the amateur’s unique ability to enhance international goodwill

We also need to look at the purpose of amateur radio in the broader scope of the available radio services (LMRS, FRS, GMRS, MURS, CB, etc):

97.3 (definitions)

• a.2: Amateur radio services. The amateur service, the amateur-satellite service and the radio amateur civil emergency service.

• a.4: Amateur service. A radiocommunication service for the purpose of self-training, intercommunication and technical investigations carried out by amateurs, that is, duly authorized persons interested in radio technique solely with a personal aim and without pecuniary interest

97.113 (prohibited transmissions)

• a.2: Communications for hire or for material compensation, direct or indirect, paid or promised, except as otherwise provided in these rules;

• a.5: Communications, on a regular basis, which could reasonably be furnished alternatively through other radio services.

In that scope, what kinds of messages does the FCC believe fit the purpose and use of amateur radio?

97.111 (Authorized transmissions)

• a.1: …to exchange messages with other stations in the amateur service…
• a.2: …to meet essential communication needs and to facilitate relief actions
• a.3: …to exchange messages with a station in another FCC-regulated service while providing emergency communications
• a.4: …to exchange messages with a United States government station, necessary to providing communications in RACES
• a.5: to exchange messages with a station in a service not regulated by the FCC, but authorized by the FCC to communicate with amateur stations

Strung all together, this (to me) paints a pretty clear picture - the FCC wants amateur radio to be a space of RF experimentation and public service. There is absolutely an argument for allowing experimentation with encryption in that scope in order to advance RF encryption technology - and I think that under existing rules it would probably be allowed. Setting up an encryption experiment on UHF+ bands (for limited interference) and publishing your intents (along with the messages) in public places would probably negate the obfuscation concerns.

However, that is not how people asking this question are generally trying to use encryption - instead, it’s usually one of two different scenarios:

1. I want to have private conversations in xyz scenario (friends, emcomm, etc).
2. The internet in 2025 is effectively broken without SSL ciphers

These are both easily covered under 97.113.a.5 - both of these actions are reasonably serviced by other radio services, and thus should not regularly be occurring on amateur bands anyways. Do they? Of course. But under Part 97 as written should they have support? No.

For the record, I think AREDN and HamWan are providing a great service and do some phenomenal research - but is it intended to replace your everyday internet browsing? No - telecomms would have an absolute temper tantrum over that being allowed. If that’s the case, and this is “simply” a separate mesh data network using repurposed commercial gear, SSL and ciphers for data encryption are not a mission-critical piece of the puzzle. Authentication and station validation likely are, but I would thing that should be acceptable under existing telemetry rules.

Similarly, is it possible to have a conversation with your friends on a repeater? Of course - and that is valuable. But if you want it to be private, there are services (radio and otherwise) that provide for that being able to happen. I personally always recommend Signal, but that is cell phone based - if you need a standalone RF function, look at Part 90 (LMRS) solutions.