3 ms·

I still remember the project in college where I embedded quite a lot of information in images. While detecting would be difficult, if NSA puts its mind to it an

I still remember the project in college where I embedded quite a lot of information in images. While detecting would be difficult, if NSA puts its mind to it and figured it out, then it would be very clear what you were doing, you can't claim randomness in your defense

klyrs 4y ago
Yep, the detectability of steganography tends to increase with information density, of course. If somebody is watching GPS traffic they could discover my (hastily conceived) location-beacon scheme, for instance. Likewise, a metadata scheme (varying time between broadcasts) could be discovered through close enough examination. But, that at least has some plausible deniability baked in, random delays are better than fixed delays in terms of network congestion.
- flavius29663 4y ago
  That was my point, there is no plausible deniability. Your cleaned-up data just happens to be the png image of some secret US bases? Good luck convincing a judge it's not intentional. If you encrypt it well enough, it might be that NSA never discover the underlying data, but that hinges on protecting the emitting source. If they get their hands on it, they can recover the keys.
LarryMullins 4y ago
The NSA might figure it out, but I doubt they'd tell the FCC about it.
ilyt 4y ago
How would you detect it then? Assuming your encryption looks like random noise and you could shape it so it looks say like sensor noise ?
- flavius29663 4y ago
  > your encryption looks like random noise well, for one, you're emitting from a balloon, so you WILL get the attention of NSA at least. Second, it's pretty trivial to find patterns in otherwise noisy signal, and NSA is expert at that and you're probably a novice. The only thing that can protect you is if you have a good enough encryption, which is hard to keep once they get their hands on the physical balloon. But even if they don't break the encryption, they can hold you in dark cells with no access to a lawyer, if they have the slightest suspicion it was indeed a spy balloon.
  - ilyt 4y ago
    How on earth they'd even know who launched the baloon? > Second, it's pretty trivial to find patterns in otherwise noisy signal, Good encryption doesn't produce patterns

klyrs 4y ago

Yep, the detectability of steganography tends to increase with information density, of course. If somebody is watching GPS traffic they could discover my (hastily conceived) location-beacon scheme, for instance. Likewise, a metadata scheme (varying time between broadcasts) could be discovered through close enough examination. But, that at least has some plausible deniability baked in, random delays are better than fixed delays in terms of network congestion.

flavius29663 4y ago
That was my point, there is no plausible deniability. Your cleaned-up data just happens to be the png image of some secret US bases? Good luck convincing a judge it's not intentional. If you encrypt it well enough, it might be that NSA never discover the underlying data, but that hinges on protecting the emitting source. If they get their hands on it, they can recover the keys.

LarryMullins 4y ago

The NSA might figure it out, but I doubt they'd tell the FCC about it.

ilyt 4y ago

How would you detect it then? Assuming your encryption looks like random noise and you could shape it so it looks say like sensor noise ?

flavius29663 4y ago
> your encryption looks like random noise well, for one, you're emitting from a balloon, so you WILL get the attention of NSA at least. Second, it's pretty trivial to find patterns in otherwise noisy signal, and NSA is expert at that and you're probably a novice. The only thing that can protect you is if you have a good enough encryption, which is hard to keep once they get their hands on the physical balloon. But even if they don't break the encryption, they can hold you in dark cells with no access to a lawyer, if they have the slightest suspicion it was indeed a spy balloon.
- ilyt 4y ago
  How on earth they'd even know who launched the baloon? > Second, it's pretty trivial to find patterns in otherwise noisy signal, Good encryption doesn't produce patterns