CIA Director John Brennan Pretends Foreign Cryptography Doesn't Exist

Re:CIA Director John Brennan Pretends Foreign Cryptography D... by poizan42 on Tuesday June 21, 2016 @01:32PM (#11947575)

Every picture contains some amount of noise. It should at least in theory be equivalent to the Halting problem to decide whether this noise was generated by an algorithm or truly random.

But there's a lot of practical issues here. If you just add noise then it may raise suspicion merely by there being more noise than expected. So you may need to "move the existing noise around" or remove the existing noise which gets more problematic to do without leaving artifacts. And of course most of the noise may actually be following some patterns that means that the added/substituted noise must also correctly follow as not not raise suspicion.

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Re:CIA Director John Brennan Pretends Foreign Cryptography D... by Natanael_L on Tuesday June 21, 2016 @06:53PM (#11950119)

Couldn't you in theory solve it by using high quality originals and manipulate the compression algorithm to introduce controlled noise that then decodes to your message? That way you can make the noise look more natural than with approaches like modifying existing compressed files.

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Re:CIA Director John Brennan Pretends Foreign Cryptography D... by deelowe on Tuesday June 21, 2016 @04:48PM (#11949279)

Exactly. I don't know enough about the topic personally, but I'm genuinely curious if stenography is detectable enough to provide a viable list of targets.

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Re:CIA Director John Brennan Pretends Foreign Cryptography D... by nxzero on Tuesday June 21, 2016 @09:54PM (#11951050)

Yes, steganalysis is used to flag material is irregular based on a number of factors:

https://en.m.wikipedia.org/wiki/Steganalysis

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Re:CIA Director John Brennan Pretends Foreign Cryptography D... by deelowe on Wednesday June 22, 2016 @10:53AM (#11954373)

Thanks!

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