Schneier on Security
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December 26, 2013
"Talking to Vula" is the story of a 1980s secret communications channel between black South African leaders and others living in exile in the UK. The system used encrypted text encoded into DTMF "touch tones" and transmitted from pay phones.
Our next project was one that led to the breakthrough we had been waiting for. We had received a request, as members of the Technical Committee, to find a way for activists to contact each other safely in an urban environment. Ronnie had seen a paging device that could be used between users of walkie-talkies. A numeric keypad was attached to the front of each radio set and when a particular number was pressed a light would flash on the remote set that corresponded to the number. The recipient of the paging signal could then respond to the caller using a pre-determined frequency so that the other users would not know about it.
Since the numbers on the keypad actually generated the same tones as those of a touch-tone telephone it occurred to us that instead of merely having a flashing light at the recipient`s end you could have a number appear corresponding to the number pressed on the keypad. If you could have one number appear you could have all numbers appear and in this way send a coded message. If the enemy was monitoring the airwaves all they would hear was a series of tones that would mean nothing.
Taking this a step further we realised that if you could send the tones by radio then they could also be sent by telephone, especially as the tones were intended for use on telephone systems. Ronnie put together a little microphone device that - when held on the earpiece of the receiving telephone - could display whatever number was pressed at the sending end. Using touch-tone telephones or separate tone pads as used for telephone banking services two people could send each other coded messages over the telephone. This could be done from public telephones, thus ensuring the safety of the users.
To avoid having to key in the numbers while in a telephone booth the tones could be recorded on a tape recorder at home and then played into the telephone. Similarly, at the receiving end, the tones could be recorded on a tape recorder and then decoded later. Messages could even be sent to an answering machine and picked up from an answering machine if left as the outgoing message.
We gave a few of these devices, disguised as electronic calculators, to activists to take back to South Africa. They were not immensely successful as the coding still had to be done by hand and that remained the chief factor discouraging people from communicating.
The next step was an attempt to marry the tone communication system with computer encryption. Ronnie got one of the boffins at the polytechnic to construct a device that produced the telephone tones at very high speed. This was attached to a computer that did the encryption. The computer, through the device, output the encrypted message as a series of tones and these could be saved on a cassette tape recorder that could be taken to a public telephone. This seemed to solve the problem of underground communications as everything could be done from public telephones and the encryption was done by computer.
Lots more operational details in the article.
Posted on December 26, 2013 at 6:44 AM
• 43 Comments
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This is why I don't fear the imminent death of the Internet. We can just build another one.
BTW, is there extra-Internet intelligence out there? EI, are you listening?
Mike, I disagree. Any "New Internet" would still be built on top of the same physical layer from which the gov't will never allow you to escape. Wireless? FCC. Copper, Fiber? Forget it.
"would still be built on top of the same physical layer from which the gov't will never allow you to escape. Wireless? FCC. Copper, Fiber? Forget it. "
A statement which justifies my interest in esoteric methods like neutrino, burst, and moon bounce communications. Making them useful won't be easy. Sure will be harder to control, though.
Seems like this scheme could work today. Can start with a simplified alphabet like Morse code. The keys would have been exchanged before hand. A bunch of them. The message is encrypted through symmetric crypto first. It's then encoded into touch tones. Before the message, the key identifier and maybe message length are sent. Then the message. The end of each section might use a hash or asterisk tone.
I figure if it got popular they'd just install a filter to look for so many tones in one conversation and send it to collection sites.
@Nick P Regarding the ham radio channel, a couple of days ago a man came to my door with a clipboard claiming to represent a neighborhood emergency preparedness group. He said that in the event of an emergency the police would most likely be overwhelmed, so it was only prudent to prepare to be self-sufficient. So they were building a database of names and email addresses. He was interested in health skills such as CPR and also whether I had a ham radio.
I'm all for being prepared, but the fact that there is a push to identify ham radio owners made me wonder if something else is going on.
On alternative physical layer methods, perhaps an audio signal can be hidden in automobile exhaust noise to make a slow internet. Microphones pick up the signal of passing cars, decode, and update an information store like Freenet. To relay the info, record the data to be sent on an SD card, plug it in your car which is wired with a speaker and drive.
Do you live in USA by any chance?
We can just build another one.
*cough* You mean just like what we have now? *cough*
A network serving cat videos, ads, and spam, and monitored by some spook organization. Alternatively, there's lots of "darknet" projects.
Seems like this scheme could work today.
There are oodles and oodles of methods and schemes that can work today. Dead drops and one-time pads still work just fine. Moving a plant from the railing to the patio deck as a signal still works. Morse code still works, and in the event of nuclear apocalypse, HF (shortwave) radio still works to run the entire military. Recent projects have included smoke signals via computers and vodka.
... a couple of days ago a man came to my door with a clipboard claiming to represent a neighborhood emergency preparedness group.
Did you check up on him? Most likely, he's a conscientious person who's trying to do what he says. As for hams, you can easily spot them by the giant HF antenna on the roof. There is the ARRL Field Day, which has been steady since 1933, where hams go and set their equipment up in the out of doors and see how many contacts they can make. They do this for disaster preparedness, and it's been helpful quite a few times. Remember, hams have government-issued licenses, and all of the currently licensed hams can be found in what essentially amounts to a huge public phone book.
I am a certified member of one of those CERT programs in the US. [link to FEMA] The local survey methodology that you experienced sounds like it was a bit ham-fisted (pun intended :-) ) but it is important for neighborhood teams to map their area and know what skills are available. And FWIW ham operators are required to obtain a license from the FCC in order to broadcast, so the government already knows who we are.
Regarding new Internet: People want 20Mbps speeds or better and there are over seven-billion people, good luck funding the infrastructure and getting through all the legal red-tape for land usage that these big corporations use lobbyists for; if it's not completely blocked through law through legal clause pathways.
RF actually is blocked completely. You'd have major PHY issues because of RF collision even if you could legally do high power broadcasting. Plus we'd all be getting cancer, or "accelerated cell growth"-IEEE
@ Mario Mnemonic
"On alternative physical layer methods, perhaps an audio signal can be hidden in automobile exhaust noise to make a slow internet."
That's a really good idea for stego or digital dead drop. Expanding on it, I thought about getting emergency messages out of a building while it was attacked or under siege that way. Also came to mind were (a) sound of an air conditioning system or (b) ultrasound embedded in a normal message like recent malware discussions. The latter might also be megaphoned. A pre-recorded response might be doing more than it appears if people inside have backup. ;)
There was also some potential in the so-called LiFi local area network. One might disguise a broadcast stream as the fluctuations of a seemingly broken outdoor light (esp flourescent tube). The fluctuations are actually encoded messages that a hidden camera can see.
Another light-based design I've considered was one of those LED signs used in advertising. Variables that might be useful for covert channels include number of lights that are on, rate of scrolling, and which message is scrolling. Additionally, there are often text art before, inside or after messages. It might be a signaling mechanism in and of itself.
Both your concept and mine are immune to the kind of RF jamming that's likely to occur when LEO/intelligence agents show up [assuming an internal power source]. They might also go undetected entirely. Plenty more ideas out there waiting for us as Brian M pointed out.
Bonus points: does anyone know of an exhaustive attempt to catalog every potential form of stego that's actually useful in practice? (Not commonly known papers saying "audio," "JPEG's," "spam," etc.) I'm sure people have thought of something cool I missed with excellent covert potential. Both the car exhaust and the SPAM were pretty clever. The rest I mentioned were my own work.
Re LiFi: An update on that for people here who enjoyed my last link on it. It's now over 1Gbps. :)
I'm surprised no mention of acoustic couplers..
I wonder what the cipher was? It'd be trivial for first world nations to intercept and reverse this. In fact they probably did given the politics in the region at the time of this story..
@ Nick P
Bonus points: does anyone know of an exhaustive attempt to catalog every potential form of stego that's actually useful in practice?
PDF formats are great, multiple data types handled in the document with various compression and data formats supported internally. Just like using obvuscated code using java script (though PDF's read more as nroff/troff/SGML).
I've been loath to look at PDF format in more detail because it's a mess. Perhaps, though, that's what makes it a good suggestion and stego. And SGML? Well, I worked with that (and XML "Draft") a long time ago. Let's just say it would make good stego even with plaintext because it was such a godawful language that the analysts would probably ignore or skim the SGML files.
Btw, I can't remember if I mentioned this during your last comment. You seemed to be absent for long enough that I was concerned about you [given what you posted in the past]. Glad to see you're still around and online. ;)
The whole article is worth reading. Especially the end, which reveals that much of the elaborate security was defeated by operatives who got arrested for unrelated causes, revealing a meeting. All attendees were captured, along with some very incriminating plaintext files. Encryption only prevents disasters like that if you use it.
Thanks for all the fish! Unfortunately, there's no such thing as a comprehensive list of "stego that's actually useful in practice"... Based on what is known thus far, such a thing is as unlimited as human free will...
+1 for @Mario Mnemonic's very plausible scheme that couldn't be shut down without very significant public backlash!
"...The end...which reveals that much of the elaborate security was defeated by operatives who got arrested for unrelated causes, revealing a meeting. All attendees were captured, along with some very incriminating plaintext files. Encryption only prevents disasters like that if you use it."
Yes, I agree. People can be the weak link. They become careless and complacent. They will choose the most "convenient" method of communications. That tends to leak or weaken encryption.
That is the hard part. If you look at the recent events you will see that most major news outlets had no skills at encryption. That lack of skills slowed the release of data.
Encryption is multifaceted. We have to make encryption easier to use - or educate people how to use complex encryption.
Further, we must discover which encryption channels and/or methods have been broken and which have not. That will be a moving target - but it can be done.
Further, we must discover which encryption channels and/or methods have been broken and which have not. That will be a moving target - but it can be done.
Actualy it cann't be done unless those who have broken a channel have poor OpSec themselves (which is in the general case very unlikely).
Put simply the way you discover if your communication channel or encryption is secure and undetected is to "seed it" with false information that will provoke a recognisable response and wait to see if your adversary "bites". If they don't then it does not mean the channel is secure and undetected. Likewise if they do respond you don't know if the encryption has failed, or traffic analysis on communications has revealed the channel, or if it's down to one of a myriad of "human failings" (as in this case).
Further any recognisable response from your adversary is likely to be at the least expensive in resources at worst terminal to you, your organisation and many involved.
So as a general case it's ill advised to test, and it's way way better to mittigate in some way. Secret Societies and other "undesirable" organisations have learnt the hard way that an "independant cell like" organisational structure offers many advantages not least because it minimises communications channels and oportunities for human errors.
A second issue is the trade between human limitations and technical solutions. It's known that all usable encryption systems can be done by a single individual with "paper and pencil" but do you realy have the concentration and memory required to do it reliably and frequently under preasure? If you can concratulations that makes you more or less unique in the espionage world. Which is why technical solutions are prefered in most cases, the simplest of which is the One Time Pad (OTP).
The problem with technical solutions is "deniability", the easier they are to use generaly the more obvious they are as a piece of clandestin equipment. For instance the OTP system is in theory about as secure as you would ever need, but it's very fragile with regards the security of the Keying Material (KeyMat). Any one who sees the actual "pad" is going to ask questions and there is little or no deniability about it.
Thus a good deal of effort is required to hide technical equipment even from quite trivial searches. In the case of OTP pads often this was tryed with "books" or "trade catalogues" but usually an experianced searcher will be suspicious and can usually quite easily check the "book" to see if it's real or not. If it is a real "off the shelf" book it is usually not at all secure with "simple usage". Thus requiring a more skilled and disiplined operator to follow the considerable effort required (sum multiple key streams) to keep a "book code" even moderately secure.
I could go on at length about other issues (such as "resends") that cause other significant security weakening problems but the general point to note is complex to use systems and error prone humans usually create more problems than they solve. And simple to use systems are generaly based on easy to recognise technical solutions.
So such technical solutions have to be at best "dual use" where the secondary use is more obvious. Things such as packs of cards and pocket calculators and these days personal IT devices have been tried but they all have failings.
Similar issues apply to "communications" which is why they need to be very carefully thought out and generaly the less high tech the better.
Setting up your own little dark net is quite trivial using something like Retroshare. It is in the Debian based Linux distributions and is also available for Apple Macs. It works. The impossible part is getting friends and family to sign up and actually use it.
Clive: This reminds me of the numbers stations blurting out computer voice generated digits on the shortwave bands. I imagine that these numbers the stations Tx are intended to be decoded by hand, using a one time padbook - old school style.
Obviously, as you have already mentioned with these systems the hardest thing is getting the keymat "in" without being detected. If I recall correctly there is an example of a codebook so small it fit inside a walnut shell on display at the National Crypto Museum supposedly seized from a KGB operative.
Now, of course in the modern era (I guess post Diffie Hellman and the asymettrical crypto "revolution" that followed in the mid to late 70s) where two parties can key and establish an encrypted channel over an insecure network much of this stuff would be resigned to the trash can of history .... and yet to this day the numbers stations keep transmitting.
Given the power levels required and the amount of money in electricity it would cost to keep such transmitters online it would indicate that they are still actively being used.
I guess they feel that a shortwave receiver and a pencil and paper would get less scrutiny than any kind of electronic equipment - which I personally think is ludicrous this day and age where everyone has smart phones, laptops etc and ubiquitous connectivity. Rather than smuggling in keying material they may instead pre-arrange prior to the agent's departure to use something available, e.g. the local major paper for the area's 10th page every Friday or perhaps go for a book they are likely to find over in their destination country. Using an easily memorized page number of say the Quran or Bible would be a choice depending on destination with futurekey material choices decided using their established channel before their pad runs out.
I recall finding out in the early 00s that DTMF tones were considered metadata (like caller/recipient ANI billing phone number info) and thus did not require a warrant to intercept.
(A corollary is that NSA has most of our credit card and bank and brokerage #s on file if we ever entered them via touchtone from our personal phones.)
One wonders whether the clarification on DTMF being metatdata was driven by this South Africa incident or an earlier one.
One also wonders whether the technical protocol decision to move DTMF from inband to outofband signalling was purely a phreaker mitigation measure or was also subject to some measure of NSA influence to widen and legally more cleanly justify their data collection.
I recall back in 1982, Union County College New Jersey Office of Disability Services used an analog phone and cassette answering machine with 1960s teletype to receive and record messages from deaf translaters and deaf students. Clever people cope.
( posted Dec.27,2013; 8:22AM )
"Actualy it cann't be done unless those who have broken a channel have poor OpSec themselves... The problem with technical solutions is "deniability", the easier they are to use generaly the more obvious they are as a piece of clandestin equipment... such technical solutions have to be at best "dual use" where the secondary use is more obvious..."
That is rather pessimistic and defeatist view. But, you make a good case. I would hope equally bright or even brighter people reside outside of the NSA. Granted the Snowden Documents may have been a lucky event - it does show there is a limit to "OpSec" at high levels within the NSA.
Here is Obama's legal solution. From what I can tell it only adds layers of lawyers to the brew. I have my doubts about its efficacy.
'Report and Recommendations of The President’s Review Group on Intelligence and Communications Technologies'
If any of you think that this report will change the mass collection of data say so. I think the names of the parties will change but the mass collection of data on Americans will remain the same.
@ Mike the goat
"I guess they feel that a shortwave receiver and a pencil and paper would get less scrutiny than any kind of electronic equipment - which I personally think is ludicrous this day and age where everyone has smart phones, laptops etc and ubiquitous connectivity. "
I would think so. Then I tell myself I'm wrong, they're right, and how so. First thing that comes to mind is a smoke screen. Those devices you mentioned can all be hacked & spied on in a ridiculous amount of ways. Anyone relying on such gear might get compromised easily. If COMSEC is handled by dedicated, hidden gear, then all the normal communications devices can be used to further the cover identity. Every time they're intercepted it just shows those watching that you're not a spy.
The spies don't even have to keep the shortwave receiver in their homes. They could be stored somewhere with no connection to them and that allowed the spy plenty of time to shake off any tails.
That the system has only two points of compromise is a compelling argument in itself.
@35uhf3iuuh "I'm surprised no mention of acoustic couplers"
From about a third of the way down the article "By chance a friend gave me an acoustic coupler that he was about to throw out" he then continue to explain experiments and development "This seemed to be the real breakthrough. I adapted our encryption program to work with the acoustic modem and recorded the output on a tape recorder. This I took to a public telephone booth and played back to my answering machine. Then I played the answering machine `message` back into the modem and the computer deciphered it successfully. As the plaintext message appeared on the screen I realised that we had finally discovered an absolutely safe method of communicating with the underground using computers."
@ Nick P
Thank you for the concern, this last year has been like a really bad spy novel, including a cast of characters that resembles Black Adder/Books.
You and others have given comfort to both me and my mathematician friend. At least I have had the chance to read your comments on secure components and platforms, they can be considered thorough and almost exhaustive. Really appreciate your contribution to the community.
I plan to submit two posts for the squid this weekend. Don't want to piss off the moderator by getting too far off topic.
@ Nick P
Funny you should mention XML, most of the corporate and third party big data spyware uses XML. Look at facebook's API fbconnect.
@ Mike the Goat, Nick P,
Those devices you mentioned can all be hacked & spied on in a ridiculous amount of ways. Anyone relying on such gear might get compromised easily.
The Russian's have almost always been ahead of everybody else at EmSec (the US about the worst due to being "gadget happy" not "resource constrained"). They still apear to be well up on it, if the "Moscow talking rock dead drop" fiasco of a few years ago is anything to go by. So on that score I'd study the Russian field craft well, especialy their Comms OpSec (when coruption is not involved as was the case in the VENONA OTP failure).
Historicaly they ran circles around all the Five-Eyes, Israel & EU and EU countries and it was the lack of hard currancy that limited their activities.
But importantly today from the likes of CarrierIQ and similar "test & tech support" and NSA backbone slurping I would assume that any mobile coms enabled device (even if just NFC) is compromised "out of the box" as a starting assumption.
And if you remember a while ago I stated that I did not think it possible to make any modern Consumer Of The Shelf ICTequip Level III advasary safe.
As I've also said befor single sheets of paper B4 pencil ontop of a glass surface you amonia clean immediatly after use is the way to go especialy if your paper is nitrate or permaganate impregnated to be fully self consuming if lit (or use genuine "rice paper" with a little "bacon cure" if you also want swallowing as an option).
As for number stations depending on the frequency not much power is required you can "work the world" with AM 40meters at 10W ERP. So high power levels are not required unless jamming is going to be an issue. As I've mentionedd befor many years ago I ran a fake numbers station to "channel hold" for a SW Pirate station during weekdays using the Apple ][ and a home brew card to generate long sequences of PBRNs (using a modified Mitchel Moore generator).
One thing "numbers stations" can be used for is making propergation predictions for working a route. Put overly simply if you can hear the station then you can work back the same route.
Oddly perhaps the US Coast Guard used to have responsability for such CW stations untill fairly recently and the keying equipment appeared on the open market. Likewise the British MI6/DWS Kaynard units have poped up on E-Bay on the odd occasion, such is the dumping of such spy related equipment post "cold war".
@ Nick P,
For stego any SGML derived markup language will work.
This is because SGML from which they are derived alows tags to be used in any order...
Now I've not tried it on this blog but it alows the use of the HTML UL, I & B tags in any order. Thus when making a Quote block you would use UL and I together. You could use the lead in pair as UL,I or I,UL and it makes no difference to how your browser displays it likewise the end pair as /UL,/I or /I,/UL. Thus if the blog does not effect the ordering you have a simple binary transmission system...
@ Nick P,
Oh I forgot to mention it's not just SGML derived files.
It's any files where "elements" can be stored in any order without effecting their ordinary usage.
Thus most if not all Word Proc files and likewise most machine code / executable files.
Likewise any file format that has redundancy in fields, where any currently unused codes get ignored rather than raising a warning.
We have seen this with "network packets" to do port knocking or other activities even through "statefull firewalls" in the past. And there are a whole host of other activities this can be used for such as causing "cache hits" due to the poor way most software stacks are set up in multi-tasking/user OS's and these in turn being used to find out the state of other processes and thus leak key bits and the like.
Good ideas on the covert signaling. Far as tradecraft, I did in fact learn mine from the Russians originally. I found it impressive that they could accomplish what they did despite our advanced tech and higher resources. The CIA vs MI6 vs KGB spy game was a breeding ground for all sorts of clever spy & counterspy methods. I learned plenty from reading all those stories (and some manuals).
Btw, I previously mentioned looking into things like meteor burst communications as a part of private communications network. I was looking at it again recently to see what improvements have been made. (Google DARPA & meteor burst for that.) I found this little gem along the way:
Declassified NSA report on meteor burst communications
(Note: The conclusion was informative to the degree I'd expect from such an organization. I won't spoil why.)
The distro I'm using tried to do pdf.js instead of downloading it. For some reason, PDF reader's save and scrolling features wouldn't work right. NoScript offered a solution: "Allow scripts from NSA.gov." I said "F*** no!" and promptly closed the tab. Did the right click save as thing instead.
I figure the NSA might already own this box but executing their scripts is just asking for it. I'll pass on that.
@ Nick P,
Yeh EME and MBC systems have been of interet to me in the past but there are other techniques, one of which will no doubt raise your eybrows more than a little...
You may remember that during WWII the British developed "window" or "chaff" to jam German radar. Put simply fast bombers dropped large quantities of metal foil strips cut to an appropriate length to "resonate" and thus reflect the radar signals. These would stay in the air for some period of time and it was noted back then that German radar signals in Europe could be heard in the UK when the foil was deployed. And there was speculation as to if it could be used to do either UHF long range comms or even what was called in the 1980's "over the horizon radar".
Later experiments showed that for similar reasons to MBC ICBM trails could be easily detected, which nearly caused the Russian's to "push the button" when very unusual MB activity tripped the automatic "in bound missile" detectors...
Now for the main Eyebrow raiser... as you may know space debris is a significant space vehical damaging issue, where even flecs of paint or small crystals of human waste can do significant damage as they move around at over 5000m/S. So you might consider any one wanting to make the problem significantly worse "crazy"? Step forward the good old USA with their idea of a "space mirror" for communications they dumped almost unimaginable quantities of "copper needles" into orbit to build a "test" mirror, most of which are still up there causing problems...
However, something else to consider, what is the beam divergance on a near IR "tri corner reflector" when up in LEO and it's effective "footprint"?
Well you could find out as the Russian GPS system has such devices on them and as the sats transmit very accurate emeriphis information pointing an IR laser or telescope at them is relativly easy. What sort of comms could you achieve by modulating your IR laser...
Nick P: fair point. I guess they are adhering to the KISS principles in the extreme, and if their use of pads has worked for them (and it has where pad hasn't been reused - let's ignore idiocy on the part of operatives) then I guess you'd continue to use a working system.
Name.withheld: I trust you are well and have received my Christmas greeting.
Clive: I didn't know you ran a fake numbers station. That's fascinating. Speaking of radiated power does anyone remember the "woodpecker" back in the 80s? I recall it was some Russian active over the horizon radar project and the transmit power was on the order of 10kw+ legend had it. I recall it was narrowed down to a certain location by amateur fox hunters.
The "Russian Woodpecker" OTHR setup was "Duga-3" located not far from Chernobyl.
Back in the days when it invaded the amateur-bands some operators allegedly found that several stations sending a stream of CW dots at about the same rate as the woodpecker-pulses would make it vacate a particular spot-frequency for a bit.
@ mike the goat
Thanks for asking, acknowledged. Was baffled by the time stamp issue. No timeouts or delivery notifications on my end. Suggests I'm the target.
And I do remember WOODPECKER, have to drag it back from long term hierarchical storage.
Pulse modulated ligiht..used by army in campaign against Geronimo...also, common in maririme situations...the Aldiss ight...
you have to be in the line of sight to "read"it...(intercept it)and active locations need not be fixed...
There woul be,, methinks, ways to set up light systems to communicate broadly among many points
name.withheld: I think its fair to say we would both be under some scrutiny. It is very interesting the delivery issues. Well, frankly they can delay receipt all they want - I am fairly certain that they will be wasting their time trying to decrypt 4096R encrypted PGP'd correspondence.
Man, I'm gone for a few days and of course a post about radio pops up. What the hell guys?! Like a security version of QRZ lol :)
--If you either already are or have considered becoming a ham (or just want to use tech. and comms. which are basically illegal but can't be enforced), you should (I figure you'd be most interested in wifi and probably be the guy to set up the 2-mile diameter wifi for hamfest :). Like a kids playground with electronics. Within a year or so, I hope to make contact w/ either a satellite, or moon/meteor bounce (it's pretty common). Finally got around to a simple implementation of a morse keyboard on the arduino w/ a ps/2 keyboard and 8-ohm speaker--simple and fun. When dealing in open source, I try to make the code as easy and readable as possible, as well as giving the user the ability to change variables like the frequency, beeps and beep-length.
You could try all your methods to get the arduino IDE on an air-gapped pc, input your encoding style, flash, then take an old recording device for VHS or other cassette tapes (or a more modern digital recording device, so long as the info is encoded prior to storage), record to a sd card or whatever and exchange (not before exchanging your OTP's). This is something everyone could do w/ someone like your lover so s/he and only s/he hears your love notes. B/c the awkwardness in suggesting these methods (then the big laugh and ok what's your phone #, I'll text which goes thru phone company and into undisclosed amount of DB's) really kills creating secure communication.
--It's been mentioned here and I've been reading long enough to remember Clive's fake number station (it was a joke to people collecting the numbers and trying to find meaning). I wasn't alive when in use, but anytime I ask my dad he scowls, "It was very annoying, it ruined entire bands". Tx power around 10MW, that evil-looking antenna array, jamming up bands; the ultimate dick move in ham radio.
RE: Potential secret comms methods
--One little one I thought up the other day which would surprise me if it hasn't already been used, using the secure paper-pencil-wipe method Clive described, taking the message and placing it in a library book (you could also check out an obscure book no one reads and leave the message but this is leaving more info and Patriot Act collects library records). The person you're talking to would be listening or already be in the library, maybe exchange the book and page #. The strength in this method is deni-ability and "going w/ the flow" since it's a public library. You would of course look for libraries cameras and not take any identifying tech. w/ you.
Mike the goat
I am fairly certain that they will be wasting their time
--Not that I need to say it since you already know, just as support; there are many attacks than you can wrap your head around. The best thing to do is to like again Clive said, plant false messages and provoke a response that you're waiting for. If it triggers a flag, halt all operations, hide all electronics you care about. This could take upwards of years so basically they are causing you self-harm by making you less secure and breaking the law actually attacking you.
Figureitout: 2mi diameter ham fest? You mean 2 mile coverage over the whole arc with an omni? Cool. The best I have done is point to point. Managed to get from my home to workplace using parabolic grid antennas and some cheap Asian WiFi gear (was slightly outside the ISM allocation...sorry FCC :-), seriously though I have seen channel 13 on international products which is centered at 2.472 but this thing had channels 15-24, which I had never heard of. In brackets it had the frequency for each band and IIRC the 15-24 were all around 1.8Ghz. Clearly some non standard mojo. Also had a very convenient tx power and RX gain adjustment, and you could enter a distance in km and it would "optimize" settings (e.g. adjust window and ack timeout). Occasionally you luck out with imported gear.) Long story short I went from the roof of my home to a friend's house approx 5 miles up the road who is on a hill. Didn't bother with WDS or mesh networking, just had two separate APs powering two antennas, one pointing at my home approx 5 degrees down and to the east and the other pointing at my workplace to the north. I used different polarization and a non conflicting channel just to err on the side of caution. Anyway the leg from there to work was 16 miles and we made it there easy on 250mW. I had a VPN to the workplace running over the network which was really cool as we ran OpenVPN in bridging mode rather than routing and thus I could actually "be" a part of the office LAN. Latency was much better than either 3G or the hideously oversubscribed service the housing community where I was residing at the time offered (they ran fiber to each condo and used it as a selling point, but of course it meant that you couldn't get plain DSL from the phone company).
But I am getting way off topic.
Moving back on topic - speaking of DTMF - I remember when the phone company used in band signalling. When you made an operator assisted long distance call you'd hear an "attention" whistle followed by the destination phone number in DTMF. I believe that someone, somewhere discovered that the whistles in Capt'n Crunch cereal boxes just happened to make a 2600hz tone. Man, we have come a long way!!
Mike the goat
--I actually never asked (nor connected to) the system he used. It was Field day actually (facepalm) and I was a little nervous b/c it was my first one (just got my tech. license); I'm usually pretty quiet when I'm nervous. I figured you've done some sort of wifi set-up given some other set-ups you do for your job. Cool only .25W, QRP is an interest of mine.
I read a QST article on July 2013 (was a bit annoying trying to get a link, plus I respect the ARRL and may write an article for QST; but there's other info) on HSMM, HSMM-MESH; where they had to relay video from the finish line back to the spectator area for a marathon b/c of environmental damage. Looks like it worked pretty good, and I have that router so I'll probably give it a shot sometime. Here's their site.
RE: Cap'n Crunch
--Yeah the guy was John Draper. Pretty goddamn hilarious that worked, reminds me of the movie "Hackers" when they had a cassette player to play tones when they needed free calls; also a hilarious movie b/c of course a rival hacker is Angelina Jolie and she gets a little "hot down under" when you beat her in a video game. Looks like he wrote some Forth too, and apparently trolled Richard Nixon in what seems like a mixture of phreaking and social engineering lol.
Mike the goat
--Ah, google...you evil company...here's the QST article I was referring to (again only like less than 10 min search):
No disrespect to QST, it's on the internet...I highly recommend the magazine to anyone, it's high quality (and if I write an article I don't care if it leaks out, only the people relying on the income of the magazine).
And after thinking about it more, the guy's wifi set-up was at his work nearby so I couldn't see and ask about. We had a dipole using trees and wasn't sure about the other antenna, but it took like at least 3 people to set up, couldn't do it alone. Similar to these:
Over break, my dad fixed up his antenna nicely using a fishing pole and spark plug to get the antenna high up in trees; made plenty of contacts (Russia, Mexico, I think Africa) and before we left I listened to a local SSB on like 80 meters (the hick operators were using the wrong mode for the band); pretty funny all the usual hillbilly ragchewing about Obama, gays, religion, and shotguns. I actually want to make an attractive antenna like a parabolic dish, yagi, or large tower; can't do it where I live though have to just use wire loops on the deck...
Figureitout: thanks for the links, I really liked the antenna design you linked to - particularly his use of cheap cutting board material as an isolator. Very clever. When I was sixteen I used a slightly modified Hayes modem to successfully connect at 75bps on 11 meters.
Used two CB radios on one end and a scanner and a CB on the other (only because we were short a second CB rig) and managed to actually get the modem to negotiate and work at full duplex. Of course this would have pi, uh really annoyed a lot of users given we had the PTT stuck on two of the forty channels and after copping some abuse in our silent periods we modified our radios by simply opening the set and turning one of the tuning caps until it was below the first channel enough not to annoy anyone and did the opposite with channel 40. It was a lot of fun, except when it lost negotiation and you got a heap of garbage followed by "NO CARRRIER". I kinda lost interest until WiFi came on the scene a decade or so later but my buddy got involved in AX25 and played with APRS - even launched a transceiver on a weather balloon along with an SSTV feed from a camera. I remember he chose a hydrogen fill after he found that the cost of helium was prohibitive given the amount of gear he was lifting. I just hoped to hell it didn't land on anyone's head. I am sure the police frown on ham gear putting holes in people's heads. Funny about that. Anyway I will end our discussion as it has gone way off topic. You know where to find me if you want to continue it without annoying the mod or anyone else on the thread.
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