Crypto is relevant because strong crypto can make centralized control more difficult. It levels the playing field for asymetric warfare.
I do not see it. Can you explain?
The biggest advantage crypto can confer on the insurgents in Iraq or Afganistan under my current models probably comes in the form of encrypting cell phones.
But if the insurgents deploy them, the occupying power declares that from now on, only non-encrypting phones are permitted and makes their declaration stick by taking control of the base stations.
The insurgents can respond by deploying radios that do not require base stations.
The occupying power’s counter-response is to set up electromagnetic-radiation monitoring to detect and triangulate the radio signals.
The insurgents can respond by replacing the use of voice conversations with the use of text messages (well, voice messages for the illiterate fighters) that are recorded by the phone and then when the user presses “Transmit” transmitted as quickly as possible to make them as hard as possible to triangulate.
But radio signals are a lot like light. Light is in fact just another form of electromagnetic radiation. So, as an aid to intuition, consider the situation in which the insurgents try to use visible light to communicate. I suppose that if there is already a lot of light, e.g., from the sun, the light from the communication devices might be able to hide. But it seems to me that the proper analogy or aid to intuition is probably the situation in which the insurgents to try use light to communicate at night because if there is enough radiation for the rebels’ signals to hide, the occupying power shuts down the sources of the radiation (TV broadcasters, base stations for unencrypted cell phones, jammers depolyed by the rebels).
I do not know enough about spread-spectrum radio to say whether it would give the rebels the advantage, but if it does, the rebels would not need to encrypt the messages, and your statement was that not spread-spectrum radio but rather crypto confers advantages on rebels.
ADDED. Come to think of it, the above analysis pertains mostly to conflicts where the stakes are sufficiently high: e.g., if insurgents tried to take over, e.g., Alaska, or whether the People’s Republic as occupier could hold Taiwan against Taiwanese insurgents backed by the U.S.. If the occupying power’s main goal is “to bring democracy to Iraq” or to deny the territory of Afganistan to al Quaida, well, that might not be high enough stakes to justify the cost to the occupying power of achieving and maintaining comprehensive control of the communications infrastructure of the occupied territory and reimbursing the population for the economic losses caused by the restrictions on communication caused by the comprehensive control. (Reimbursement would tend to be necessary to keep the population on the occupying power’s side).
I do not know enough about spread-spectrum radio to say whether it would give the rebels the advantage, but if it does, the rebels would not need to encrypt the messages, and your statement was that not spread-spectrum radio but rather crypto confers advantages on rebels.
Spread-spectrum is crypto—the idea is to select a pattern (of frequencies) that eavesdroppers can’t distinguish from random noise but which is predictable to the intended recipient.
You’re forgetting about steganography; encrypted messages can be made to look like vacation photos, music, spam or something else. Using steganography sounds complicated when you describe it, but in practice all the details are handled transparently by some software, so it’s just one-time setup.
The occupying power announces that until the insurgents stop killing innocent civilians and sowing disorder, no one in contested territory is permitted to use the internet to transmit vacation photos, music, spam, etc. Civilians whose livelihoods are interrupted by these restrictions can apply for monetary compensation from the occupying power. Music and other entertainment will still be available from iTunes and other major centralized services (unless and until there are signs that these centralized services are being used to broadcast hidden messages).
In the Malay Emergency, the occupying power, which won the conflict, required 500,000 civilians to relocate to new villages surrounded by barbed wire, police posts and floodlit areas. Compared to that, restrictions on the internet are mild.
Also, the need for steg reduces the bandwidth available to the insurgents—perhaps below the level required for voice communication, which requires the communicators to be literate, which denys the communications channel to a large fraction of the world’s insurgents.
“One-time” is a bit of a stretch (all it takes is being found out once to greatly impair the value of any particular method), but yeah—steganography is an established and worthy technique.
You are thinking about radio communication much more than I was. My thought process centered on encrypted use of the internet to allow insurgents to communicate both with each other and with sympathizers or allies that are elsewhere. I agree with your analysis that crypto is unlikely to do much in terms of radio communications.
I do not see it. Can you explain?
The biggest advantage crypto can confer on the insurgents in Iraq or Afganistan under my current models probably comes in the form of encrypting cell phones.
But if the insurgents deploy them, the occupying power declares that from now on, only non-encrypting phones are permitted and makes their declaration stick by taking control of the base stations.
The insurgents can respond by deploying radios that do not require base stations.
The occupying power’s counter-response is to set up electromagnetic-radiation monitoring to detect and triangulate the radio signals.
The insurgents can respond by replacing the use of voice conversations with the use of text messages (well, voice messages for the illiterate fighters) that are recorded by the phone and then when the user presses “Transmit” transmitted as quickly as possible to make them as hard as possible to triangulate.
But radio signals are a lot like light. Light is in fact just another form of electromagnetic radiation. So, as an aid to intuition, consider the situation in which the insurgents try to use visible light to communicate. I suppose that if there is already a lot of light, e.g., from the sun, the light from the communication devices might be able to hide. But it seems to me that the proper analogy or aid to intuition is probably the situation in which the insurgents to try use light to communicate at night because if there is enough radiation for the rebels’ signals to hide, the occupying power shuts down the sources of the radiation (TV broadcasters, base stations for unencrypted cell phones, jammers depolyed by the rebels).
I do not know enough about spread-spectrum radio to say whether it would give the rebels the advantage, but if it does, the rebels would not need to encrypt the messages, and your statement was that not spread-spectrum radio but rather crypto confers advantages on rebels.
ADDED. Come to think of it, the above analysis pertains mostly to conflicts where the stakes are sufficiently high: e.g., if insurgents tried to take over, e.g., Alaska, or whether the People’s Republic as occupier could hold Taiwan against Taiwanese insurgents backed by the U.S.. If the occupying power’s main goal is “to bring democracy to Iraq” or to deny the territory of Afganistan to al Quaida, well, that might not be high enough stakes to justify the cost to the occupying power of achieving and maintaining comprehensive control of the communications infrastructure of the occupied territory and reimbursing the population for the economic losses caused by the restrictions on communication caused by the comprehensive control. (Reimbursement would tend to be necessary to keep the population on the occupying power’s side).
Spread-spectrum is crypto—the idea is to select a pattern (of frequencies) that eavesdroppers can’t distinguish from random noise but which is predictable to the intended recipient.
Thanks for the info.
You’re forgetting about steganography; encrypted messages can be made to look like vacation photos, music, spam or something else. Using steganography sounds complicated when you describe it, but in practice all the details are handled transparently by some software, so it’s just one-time setup.
The occupying power announces that until the insurgents stop killing innocent civilians and sowing disorder, no one in contested territory is permitted to use the internet to transmit vacation photos, music, spam, etc. Civilians whose livelihoods are interrupted by these restrictions can apply for monetary compensation from the occupying power. Music and other entertainment will still be available from iTunes and other major centralized services (unless and until there are signs that these centralized services are being used to broadcast hidden messages).
In the Malay Emergency, the occupying power, which won the conflict, required 500,000 civilians to relocate to new villages surrounded by barbed wire, police posts and floodlit areas. Compared to that, restrictions on the internet are mild.
Also, the need for steg reduces the bandwidth available to the insurgents—perhaps below the level required for voice communication, which requires the communicators to be literate, which denys the communications channel to a large fraction of the world’s insurgents.
“One-time” is a bit of a stretch (all it takes is being found out once to greatly impair the value of any particular method), but yeah—steganography is an established and worthy technique.
You are thinking about radio communication much more than I was. My thought process centered on encrypted use of the internet to allow insurgents to communicate both with each other and with sympathizers or allies that are elsewhere. I agree with your analysis that crypto is unlikely to do much in terms of radio communications.