"Currently, encryption is forbidden"
Ah, those Nazi spies, one needs to forestall their cunning ways or they will surely dance on our beaches!
Seriously though, how would they know there is encryption? Do the waves change colourr?
UK regulator Ofcom is looking for radio hams' opinions about proposed changes to spectrum and amateur licensing. In exchange for giving up some spectrum, hams are getting access to new spectrum in the 470 kHz and 5 MHz bands that the Ministry of Defence is happy for them to use. Users of that spectrum will have to quit if the …
The data would have the characteristics of purely random data. The goal of algorithms like AES is to produce an output bit stream that is 'random' (so far as a statistical analysis is concerned) no matter what the input data is. Algorithms such as the one Enigma implemented aren't so good at that, which is what let Turing and chums get into it.
What I'd like to know about this proposal is whether this helps licensed amateurs avoid the interference caused by illegally imported US spec Homeplug devices.
how would they know there is encryption?
Technically the licence rule isn't "no encryption", it's "not enciphered", see BR68:
http://www.psc.gov.uk/static/archive/ra/publication/ra_info/br68r11/br68.htm
particularly the bits about:
(b) Signals (not enciphered)...
and
1(6) The Licensee may use codes and abbreviations for communications as long as they do not obscure the meaning of, but only facilitate, the communications.
Essentially the messages have to be in clearly understandable form. There are probably exceptions for Geordies...
Yet another G3 (I assume)
Nope, a G8 as-was. F1 these days, so a bit out of touch with the details. I had the BR68 to hand.
I do see that the new description has been changed to say encrypt instead of encipher, an interesting if subtle change:
11(2) The Licensee ... shall not encrypt these Messages for the purpose of rendering the Message unintelligible to other radio spectrum users.
...
11(3) The Licensee may use codes and abbreviations for communications as long as they do not obscure or confuse the meaning of the Message.
BR68 is a widely recognised name for the document known as "UK AMATEUR RADIO LICENCE, Section 2, Terms, conditions and limitations", something I, a mere G7, recognised immediately.
For those still looking at a document bearing the reference BR68, the current version of the document (http://licensing.ofcom.org.uk/binaries/spectrum/amateur-radio/guidance-for-licensees/amateur-terms.pdf) sates:
"11(3) The Licensee may use codes and abbreviations for communications as long as they do
not obscure or confuse the meaning of the Message."
"Seriously though, how would they know there is encryption? Do the waves change colour?"
D'oh!
If it sounds like English (or another spoken language), it's not encrypted. If sounds like backwards high speed audio garbage, it's encrypted. I'm guessing you've never actually heard radio ham communications.
yup. 455, 465, 470khz were widely used in IF strips BUT its unusual to have an IF strip exposed to the 'ether'. Shielded and screened and fed from a mixer.
IN practice to receive such a frequency the LO would be exactly twice that - 940Khz.
I suspect that if you were slightly off, there would be some unwanted heterodyning, though.
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That's not how RAYNET works. There's a ham at each end, liaising with the emergency services and passing non-amateur messages over standard amateur frequencies (which would normally be outside the licence terms). The change proposed is that if the emergency services in question ask for the comms to be encrypted, they can be. RAYNET operation is only permitted on the express demand of a selective list of emergency services, plus a few training exercises each year, not at the whim of individual amateurs.
Not every blue light service can afford TETRA/Airwave. The billing system is that they take the heaviest usage on any day of the billing period (usually a month) and then apply that for every day of that month. If you're a small service, or one doing mostly "events" such as St. John, Red Cross or any number of the other voluntary/privates, this is unaffordable, leaving aside the issues such as management of talkgroups, security of the handsets and cost (a typical large football stadium will require over a dozen handsets for first aid teams alone, many come in at over £1,000 each). For operators far away from base stations (lifeboats, mountain rescue, cave rescue etc) its even less of a viable option.
There are also resilience and capacity issues with TETRA, I've been on operations with a major statutory service where it has simply failed for hours at a time in a major metropolis with no "disaster" issues such as enviornment or power issues for events that occur every year.
There is a privacy issue with the use of open VHF, sometimes in the normal course of events patient details have to be transmitted from a control to a vehicle (or similar) and this has always caused some concerns. In the event of a major incident, the press are likely to be swarming around more than normal and it might be nice for a relative not to get their first notification that the nearest and dearest have snuffed it from twitter or being doorstepped by some reporter with a scanner. In such circumstances I would think encryption the lesser of two evils, although I realise that any commonality for inter-operation might then lead to the means to defeat this being publicly available....
and it might be nice for a relative not to get their first notification that the nearest and dearest have snuffed it from twitter or being doorstepped by some reporter with a scanner.
Not to mention the problems of dealing with mass panic if some reporter gets the wrong end of "maybe we should get some bio-hazard suits up here" when the actual problem is a burst pipe at a sewage works?
Sadly, the heyday of RAYNET operating at small events on behalf of user services such as St John and Red Cross has largely passed. Most of these organisations now have their own handhelds and do their own comms (I declare an interest: I used to examine their users' competence to operate). As a result RAYNET groups are nothing like as active as they were before about the mid 1990s.
RAYNET now really only come into its own at large events (either in numbers or especially on area covered), maybe a cut cable or fire in a telephone exchange (happens surprisingly often) - or an actual disaster. But because members don't operate as frequently (I used to go out two, maybe three weekends a month in the summer) nor with the sort of ad-hoc (and variable) intergroup working we used to do; I wonder how the lack of that constant practice, doing real comms, affects operational efficiency and cohesiveness.
I worry about encryption, it has always been strictly verboden, and my concern is that it will be misused. I also wonder how it is going to be achieved in the field on an actual event. Practically, encryption really only makes sense on a digital circuit (voice or data). But doing it "on demand", and therefore in clear the rest of the time, is not going to be easy. will we see voice scramblers on analog circuits?
Then there is the tendency for "incident commanders" to take whatever is given (and still ask for more). Which in this case means: encrypt everything. Then, suddenly, one of the major checks / balances disappears because no other amateur can listen in. And trust me: there are are *always* people who listen and, if they can find a reason (however specious), they *will* complain.
How is the use of encryption going to be policed? Who is going to do it?
I am a bit curious about why this is being introduced now - in these times of universal monitoring of everything by our lords and masters. As I mentioned above, the onus has always been on what might charitably be called "self regulation". There has never been much in the way of official monitoring. What there was, generally relied on complaints made or tipoffs. Perhaps someone can enlighten us?
RAYNET is not universally loved on the bands and I suspect that being *allowed* to use encryption will prove very divisive. Therefore, yet more reason for grumbling and internecine strife - which probably means even more "unintentional interference" than usual for operators at an event to deal with.
Sigh...
They heyday of RAYNET being involved in events ended abruptly around 2000. I remember that well, because I was involved in event management/marshalling lots of events from the late 90's to the mid 00's.
The main reason they ended up defunct was that RAYNET had pretty crap equipment, yet were cripplingly expensive. Sending radio messages involved sending people over to the RAYNET tent with a message and they used to try and send the message to somebody in a range rover, who might get it if there wasn't too much interference, who might then relay to another station or pass said message onto the intended recipient if the radio operator could find him, and wasn't too busy with his tea and biscuits.
This was inefficient and ineffective (many a message just vanished into the ether) and the range on the equipment they used was pathetic. They were also rather expensive. It ended quite abruptly when it was realised that the then newish PMR446 had better range, despite RAYNET having the advantage of 20 foot antennas, caravans full of equipment and an army of experts.
Comparatively PMR446 was comms heaven since everybody could simply pass messages to each other directly without middlemen being involved. Word quickly spread and everybody involved in eventing kitted out with similar kit in either PMR446 or PBR. Mobile phones becoming prevalent was the final nail in RAYNET's eventing coffin in urban areas where PMR or PBR weren't feasible due to other users.
Just the POV from the other side of the fence. :)
Good point about the privacy issue.
I was once on a RAYNET Exercise providing communications on behalf of a user service on an equestrian endurance trial. A horse participating in the leisure ride was kicked by another and had to be destroyed.
The rider was in a vehicle with a RAYNET operator when the control station needed to communicate the imminent arrival of the knacker's van to user service personnel on site. The message sent, something like "A recovery vehicle is en-route and will be with you within 30 minutes" was close to breaking licence terms at the time.
UK Amateurs have had access to 470 kHz and 5 MHz bands for quite a while, but you had to apply for individual permission from the MOD under a variation of the individual licence. The proposal is that these will now come under the general licence as per the other bands. Also radio amateurs have been using ciphers since day one. What is morse if it is not enciphered?
It is a cipher, but with no more security than any other mono-alphabetic substitution. It's a little bit better than Julius Caesar is claimed to have used, because the dot-dash sequences are not all the same size, and you could argue that it's data-compression rather than a cipher, using a multi-dimensional binary straddling chequerboard.
In the end, saying Morse is a cipher is no more useful than saying written Greek or Hebrew, or written English, is an enciphered version of the spoken language.
It's a little bit better than Julius Caesar is claimed to have used, because the dot-dash sequences are not all the same size
That much is irrelevant' symbol demarcation in Morse is by way of timing. So the symbols are already all separated in the stream.
IOW, there's less "security" in Morse than in a Caesar cypher. And that is by design.
Vic.
Data in encoded to allow transmission in clear using a suitable code e.g., Morse, Murray, LPC
Data is encoded then encrypted (or vice versa) to allow transmission in secret using a suitable code/encryption pair. A one time pad (encryption) and Morse (encoding) is but one example.
My recollection of RAYNET was that they had a disproportionate sense of their own importance.
I'm more than surprised they are still in operation, I would have thought that the advent of alternative means of communication rendered the whole concept as inefficient and outdated.
I would have thought that the advent of alternative means of communication rendered the whole concept as inefficient and outdated.
There are few long- or medium-distance alternatives which can survive a real disaster, especially once mains power goes out. Think earthquakes, floods, etc. RAYNET types may well have got snippy over the CB types who thought that any problem could be solved with a bigger linear, but by and large they were well-trained and much more aware of the technical problems presented by any given site.
It's true that they offer few advantages over modern PMR equipment or mobile phones when the basic infrastructure is working well, during sporting events for example, but in most cases RAYNET helps out at such events mainly to train its own members. Remember that the foundations of RAYNET date from the 1953 storms where the official infrastructure collapsed, and amateurs (in violation of their licence conditions) were the only point of contact between shipping in distress and the rescue services. That's what it's meant for, and is why it can officially only be called out by the "blue light" services, and a few others.
Good point.
Handheld radios have a range of at best a few miles because their power levels must remain within safe limits. Vehicle PMR radios are usually limited to allow operators in different areas to use the same frequency.
To increase range, base stations are added, either on a site or a hilltop location. The range of these is, again, limited to what is necessary to free the channel to users in other areas. Tetra and mobile networks all rely on base-station to mobile operations. Due to planning restrictions, these base stations tend be grouped together.
PMR/Tetra & mobile networks also have a fixed capacity that can become overloaded at times of high traffic..After the 1997 M42 pile-up the mobile networks were over-whelmed by survivors trying to tell their loved-ones they were okay. This prevented the rest-centre staff calling back to their control centre to report their arrival.
Consider an emergency situation: comms. traffic is likely to be high at times, meaning that lower priority messages never get through. After an incident in 1998 that RAYNET attended, the feedback from the emergency rest centre staff was that it was the first time they knew what was going on, allowing them to better prepare for arrivals. This is the contribution that RAYNET is most likely to be in a called on to provide in an emergency. Encryption in such circumstances would be required if they were passing personal information such as casualty or survivor lists.
Now consider an incident that coincides the loss of one or more base stations. Networks are designed to provide coverage efficiently. They are not designed to provide redundancy over their entire coverage area so there can be large 'dark areas' as there were in 1953 when the emergency serviced relied on fixed telephones. Radio amateurs are in many cases best equipped to provide communications in such areas, just as they were in 1953. If encryption were essential during such an incident, I am sure it would be overlooked by OffCom.
One further point: We are already allowed to permit a member of a user service to operate our radios under supervision.