Ping: Phil Hobbs

Dunno. I just see one post.

There are two basic ways of adding side-channel data in an image: metadata and steganography.

Metadata is easily stripped out, but steganography is a much tougher nut to crack--it's embedded in low-order bits of the low-spatial-frequency components of an image. Good steganography even survives printing + scanning a paper copy.

Cheers

Phil Hobbs

Ah! You may review the whole thread here if you don't wish to visit the Usenet group:-

I've long been interested in steganography. I have a suspicion that 'bad guys' use it to pass messages to one another.

Interesting. Do you know a lot about the subject?

Thanks for responding, Phil. :-)

--
David B. 
Devon, UK

There have been steg progams around for at least 25 years now. In the early days they weren't so viable because picture files back then were really tiny compared with today. So although steg's been around in conventional art for countless centuries, it's only relatively recently that it's become viable to use it in digital images. So do the bad guys use it? I doubt it. Conventional encryption most likely, but that's just a guess as I'm very out of date with this kind of thing.

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I'm by no means an expert on it, but some IBM colleagues of mine did some interesting work on that back about 2000-ish, so I took an interest.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC / Hobbs ElectroOptics 
Optics, Electro-optics, Photonics, Analog Electronics 
Briarcliff Manor NY 10510 

http://electrooptical.net 
http://hobbs-eo.com

Thanks for clarifying, Phil.

Do you agree with the conclusion reached by 'Cursitor Doom' or do you think it possible that steganography COULD be being used for nefarious purposes?

Are you aware of any specific software that I could use to determine if an image DOES have a secret 'hidden below the surface' as it were?

--
Regards, 
David B.

Depends. Probably if you took the image from Creative Commons or someplace and hacked it up, the steganography would probably be detectable. Even if it were very well encrypted and so not recoverable by ordinary means, just the fact that the noise floor of the image changed would be a bit of a pointer.

With an original image it would be much harder to spot, I expect.

No.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

Your comments much appreciated.

Thank you, Phil :-)

--

[Cross-posted to 'Betty' group]

On Tue, 11 Jun 2019 20:00:53 +0100, "David B." crossposted:

I recently looked up the definition of Cyberstalking (a serious crime in the UK)

//Cyberstalking:

Cyberstalkers often claim that they are just flaming (AKA "investigating"), but newsgroup stalking is more than just dogging someone's posts with flames. This behavior rises to the level of Cyberstalking when someone does it consistently over an extended period of time.

Other actions that constitute Cyberstalking include:

doing extensive research on the victim's private life and using it to intimidate or harass

making threats of continuing online harassment

threats to cause harm to someone in "real life"

using the internet to engage in activity that is intended to cause harm to someone in "real life"

impersonating another person in newsgroups or chat rooms

repeatedly lying about someone to the extent that meets the legal definitions of defamation or libel//

Remind you of anyone ? If it doesn't, here's a clue:

Remember, DAVID BROOKS, every time you STALK, the bots pick up your "special" page, and you get more hits on Google. Not as a *good guy*. or

Your psychopathic behavior will soon be known to all. []'s

--
Don't be evil - Google 2004 
We have a new policy  - Google 2012

Bear in mind that storing data inside images is only one kind of steganography. Another that piques my interest at present is hiding the output of a voice codec inside another audio stream. CODEC 2 looks particularly suitable. But essentially you can hide data inside any other bulk data format. It would be trivial to store large amounts of data inside any PDF file, for example. The whole thing is a big lookup table of assorted data objects that reference each other, so you can insert a new one and no-one will notice it's not referenced.

Clifford Heath.