Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Old June 9th 19, 01:04 PM posted to sci.electronics.repair
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Default Ping: Phil Hobbs

Hi Phil

Do you have the expertise to satisfy the query of a poster called
'Viking' - he's asking his question in another group?

MID

http://al.howardknight.net/msgid.cgi?ID=156008164700

There is now quite a thread!

--
David B.
Devon, UK

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Old June 9th 19, 09:52 PM posted to sci.electronics.repair
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Default Ping: Phil Hobbs

On 6/9/19 8:04 AM, David B. wrote:
Hi Phil

Do you have the expertise to satisfy the query of a poster called
'Viking' - he's asking his question in another group?

MID

http://al.howardknight.net/msgid.cgi?ID=156008164700

There is now quite a thread!


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
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Old June 9th 19, 10:31 PM posted to sci.electronics.repair
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Default Ping: Phil Hobbs

On 09/06/2019 21:52, Phil Hobbs wrote:
On 6/9/19 8:04 AM, David B. wrote:
Hi Phil

Do you have the expertise to satisfy the query of a poster called
'Viking' - he's asking his question in another group?

MID

http://al.howardknight.net/msgid.cgi?ID=156008164700

There is now quite a thread!


Dunno.* I just see one post.


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

https://groups.google.com/forum/#!to...al/PXtrK4qmBjE

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


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

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.


Interesting. Do you know a lot about the subject?

Cheers


Thanks for responding, Phil. :-)

--
David B.
Devon, UK
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Old June 10th 19, 12:39 AM posted to sci.electronics.repair
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Default Ping: Phil Hobbs

On Sun, 09 Jun 2019 22:31:08 +0100, David B. wrote:

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


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.



--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
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protocols constitutes acceptance of this condition.
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Old June 11th 19, 04:31 PM posted to sci.electronics.repair
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First recorded activity by DIYBanter: Sep 2006
Posts: 612
Default Ping: Phil Hobbs

On 6/9/19 5:31 PM, David B. wrote:
On 09/06/2019 21:52, Phil Hobbs wrote:
On 6/9/19 8:04 AM, David B. wrote:
Hi Phil

Do you have the expertise to satisfy the query of a poster called
'Viking' - he's asking his question in another group?

MID

http://al.howardknight.net/msgid.cgi?ID=156008164700

There is now quite a thread!


Dunno.* I just see one post.


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

https://groups.google.com/forum/#!to...al/PXtrK4qmBjE

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


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

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.


Interesting. Do you know a lot about the subject?

Cheers


Thanks for responding, Phil. :-)


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



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Old June 11th 19, 06:45 PM posted to sci.electronics.repair
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First recorded activity by DIYBanter: Jun 2019
Posts: 7
Default Ping: Phil Hobbs

On 11/06/2019 16:31, Phil Hobbs wrote:
On 6/9/19 5:31 PM, David B. wrote:
On 09/06/2019 21:52, Phil Hobbs wrote:
On 6/9/19 8:04 AM, David B. wrote:
Hi Phil

Do you have the expertise to satisfy the query of a poster called
'Viking' - he's asking his question in another group?

MID

http://al.howardknight.net/msgid.cgi?ID=156008164700

There is now quite a thread!


Dunno.* I just see one post.


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

https://groups.google.com/forum/#!to...al/PXtrK4qmBjE

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


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

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.


Interesting. Do you know a lot about the subject?

Cheers


Thanks for responding, Phil. :-)


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


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.
  #7   Report Post  
Old June 11th 19, 07:06 PM posted to sci.electronics.repair
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First recorded activity by DIYBanter: Sep 2006
Posts: 612
Default Ping: Phil Hobbs

On 6/11/19 1:45 PM, David B. wrote:
On 11/06/2019 16:31, Phil Hobbs wrote:
On 6/9/19 5:31 PM, David B. wrote:
On 09/06/2019 21:52, Phil Hobbs wrote:
On 6/9/19 8:04 AM, David B. wrote:
Hi Phil

Do you have the expertise to satisfy the query of a poster called
'Viking' - he's asking his question in another group?

MID

http://al.howardknight.net/msgid.cgi?ID=156008164700

There is now quite a thread!


Dunno.* I just see one post.

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

https://groups.google.com/forum/#!to...al/PXtrK4qmBjE

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

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

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.

Interesting. Do you know a lot about the subject?

Cheers

Thanks for responding, Phil. :-)


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


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?


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.

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?


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
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Old June 11th 19, 08:00 PM posted to sci.electronics.repair,alt.music.prayforthesoulofbetty
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First recorded activity by DIYBanter: Jun 2019
Posts: 7
Default Steganography (was - Ping: Phil Hobbs)

On 11/06/2019 19:06, Phil Hobbs wrote:
On 6/11/19 1:45 PM, David B. wrote:
On 11/06/2019 16:31, Phil Hobbs wrote:
On 6/9/19 5:31 PM, David B. wrote:
On 09/06/2019 21:52, Phil Hobbs wrote:
On 6/9/19 8:04 AM, David B. wrote:
Hi Phil

Do you have the expertise to satisfy the query of a poster called
'Viking' - he's asking his question in another group?

MID

http://al.howardknight.net/msgid.cgi?ID=156008164700

There is now quite a thread!


Dunno.* I just see one post.

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

https://groups.google.com/forum/#!to...al/PXtrK4qmBjE

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

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

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.

Interesting. Do you know a lot about the subject?

Cheers

Thanks for responding, Phil. :-)


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


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?


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.

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?


No.

Cheers

Phil Hobbs



Your comments much appreciated.

Thank you, Phil :-)

--

[Cross-posted to 'Betty' group]
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Old June 11th 19, 08:20 PM posted to sci.electronics.repair,alt.music.prayforthesoulofbetty
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Posts: 565
Default I'm drunken STALKER again !!! (was not re-Steganography (was not - Ping: Phil Hobbs)

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

A_LOT_OF_PERSONAL_NAMES_AND_PRIVATE_DATA
OFF_TOPIC_TO_ALL_GROUPS


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*.
https://web.archive.org/web/20190603181837/http://tekrider.net/pages/david-brooks-stalker.php
or
http://tekrider.net/pages/david-brooks-stalker.php
Your psychopathic behavior will soon be known to all.
[]'s
--
Don't be evil - Google 2004
We have a new policy - Google 2012
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Old June 12th 19, 12:37 AM posted to sci.electronics.repair
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First recorded activity by DIYBanter: Jul 2006
Posts: 148
Default Ping: Phil Hobbs

On 10/6/19 6:52 am, Phil Hobbs wrote:
On 6/9/19 8:04 AM, David B. wrote:
Do you have the expertise to satisfy the query of a poster called
'Viking' - he's asking his question in another group?
MID
http://al.howardknight.net/msgid.cgi?ID=156008164700
There is now quite a thread!

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.


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.


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