Talk:Black chamber

How to get round the black chamber

If you have reason to assume your communications will be monitored employ misdirection, some variant of the 'smuggling wheelbarrows' manoeuvre and other practices. I read 'somewhere' that two people communicated by both using the same email account and leaving their actual messages in the 'draft' folder so they never went over the systems - would this still work (as it is known about)? Anna Livia (talk) 19:12, 23 July 2020 (UTC)

@Anna Livia The example of two people sharing the same email account and leaving messages in the draft folder won't work, as we must assume that the service provider (that is, the email system, the internet service provider, any number of internet hosts in between) will be able to read the messages. The only truly secure method of communications is the One-time pad which is indecipherable if properly used. Cuba broadcasts coded messages daily to their operatives in the field over shortwave radio -- anyone with a portable radio can hear the message but only the holder(s) of the key can decipher it. —cosmikdebris ^talk stalk 19:57, 23 July 2020 (UTC)

As I said - there was some case in which the 'draft folder message system' was used, so the option was probably allowed for once the authorities became aware of it.

The problem with one-time pads, numbers stations etc - such systems alert anyone coming across them to investigate further.

The only secure system is one that is not obvious to 'the interceptors' but makes sense to the intended users. (The TV weather forecast maps may show a changing range of localities - which could, theoretically, be 'telling somebody something; the advert in the newspaper for 'a chest of drawers, X inches width' which is an ad for something else.) Anna Livia (talk) 11:14, 26 July 2020 (UTC)

You could get around the "public broadcast" problem by hiding the message inside some other medium, that is, for example, using a covert channel, steganography, or some other trick. But using the Cuban spy transmission one time pad example, they don't seem to care that anyone can hear and scrutinize these transmissions because they believe that the key used is sufficiently random so as to make the message unbreakable.

I'm also reminded of Jeremiah Denton, who as a prisoner of war in Vietnam in 1966 spelled out the word "torture" in a Vietnamese propaganda television broadcast by blinking his eyes in Morse code, confirming for the first time to US intel that American POWs were being tortured. —cosmikdebris ^talk stalk 15:47, 27 July 2020 (UTC)

Would variants on using the weather forecast/placenames mentioned system work (if communicants have appropriate lists of codeword equivalents)?

There will always be means of communicating information that do not alert the uninitiated. Anna Livia (talk) 20:17, 27 July 2020 (UTC)

Depending on the adversary's skills and resources, there is no such thing as an unbreakable method of securing a message, except for the one time pad. The amount of effort your adversary puts into breaking your coded message depends on the time and effort it takes to decipher it, and the value of the message itself. If it takes so much time and effort to decode the message so that the information in it is no longer of any value, your adversary would not bother. That has to be balanced with the amount of effort your recipient needs to decode the message. The weather forecast/place names example given above is certainly viable, and is in fact, an example of a covert channel; but if you require secrecy in addition to subterfuge you must be concerned with the encryption scheme, subject to all the issues above. —cosmikdebris ^talk stalk 21:30, 27 July 2020 (UTC)

And, as with the wheelbarrows/bikes 'you' have to recognise what you are looking at.

The weather/place-name (but not the Shipping Forecast, which has to be in a specific format) and similar systems can be used to transmit multiple messages to various people - each has a different list. (I have no proof that the forecasts are so used - but the places highlighted do vary at times and it is relatively low-tech).

The coders and the black chambers will co-evolve: and different systems will be more appropriate for 'one-off projects', 'repeated but distinct projects' and 'ongoing activities.' Anna Livia (talk) 23:30, 27 July 2020 (UTC)