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The hidden fingerprint inside your photos
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Leroy N. Soetoro
Jul 18, 2021, 3:03:49 PM7/18/21
to
https://www.bbc.com/future/article/20210324-the-hidden-fingerprint-inside-
your-photos
They say a picture is worth a thousand words. Actually, there's a great
deal more hidden inside the modern digital image, says researcher Jerone
Andrews.
On 3 October 2020, the White House published two photographs of Donald
Trump, signing papers and reading briefings. The day before, Trump had
announced he had caught the coronavirus and these photos were apparently
released to show that he was in rude health. His daughter Ivanka tweeted
one of the photos with the caption: "Nothing can stop him working for the
American people. RELENTLESS!"
But keen-eyed observers noticed something unusual.
The photos were taken in two different rooms in Walter Reed National
Military Medical Center. In one Trump wears a jacket, in the other just a
shirt. Coupled with public statements about his positive health and work
ethic, the implication was that he had been handling his presidential
duties all day, despite his illness. The photo timestamps, however, said
otherwise. The images were taken 10 minutes apart.
Of course, there are other possible explanations for why they were shot so
closely together. Perhaps the photographer only had access for 10 minutes,
and maybe Trump always intended to switch rooms during that window.
However, the White House can't have been happy that people noticed the
timestamps. It led news outlets and commentators to talk about whether the
images were staged for a photoshoot to project a political message, and to
question whether Trump really was working so "relentlessly" after all.
Hidden information inside digital photos can reveal much more than
photographers and their subjects bargain for
It's not the only time hidden information inside a digital photo has led
to unintended consequences. Just ask John McAfee, founder of the eponymous
antivirus software. In 2012, he was on the run from the Belizean
authorities in Central America. Reporters from Vice magazine tracked him
down and published an image of him online, under the headline "We Are With
John McAfee Right Now, Suckers". Yet without them realising, location data
embedded in the photo inadvertently revealed that McAfee was in Guatemala.
He was soon found, and detained.
These are just two examples of how hidden information inside digital
photos can reveal much more than the photographers and their subjects
bargained for. Could your own photos be sharing more details with the
world than you realise too?
When you take a photo, your smartphone or digital camera stores "metadata"
within the image file. This automatically and parasitically burrows itself
into every photo you take. It is data about data, providing identifying
information such as when and where an image was captured, and what type of
camera was used.
It is not impossible to expunge metadata, using freely available tools
such as ExifTool. But many people don't even realise the data is there,
let alone how it might be used, so they don't bother to do anything about
it before they post images online. Some social media platforms remove
information like geolocation (though only from public view), but many
other websites do not.
This lack of awareness has proven useful for police investigators, to help
them place unwitting criminals at a scene. But it also poses a privacy
problem for law-abiding citizens if the authorities can track their
activities through images on their camera and social media. And
unfortunately, savvy criminals can use the same tricks as the police: if
they can discover where and when a photo was taken, it can leave you
vulnerable to crimes such as burglary or stalking.
But metadata is not the only thing hidden in your photos. There is also a
unique personal identifier linking every image you capture to the specific
camera used, but it's one you'd probably never suspect. Even professional
photographers might not realise or remember that it's there.
To understand what this identifier is, you first have to understand how a
photo is captured. Central to every digital camera, including those inside
smartphones, is its imaging sensor. This is composed of a grid of millions
of silicon "photosites", which are cavities that absorb photons (light).
Due to a phenomenon known as the photoelectric effect, the absorption of
photons causes a photosite to eject electrons a bit like a nightclub
bouncer.
The electrical charge of the electrons emitted from a photosite is
measured and converted into a digital value. This results in a single
value for each photosite, which describes the amount of light detected.
And this is how a photo is formed. Or etymologically speaking, a drawing
with light.
However, due to imperfections in the manufacturing process of imaging
sensors, the dimensions of each photosite differs ever so slightly. And
when coupled with the inherent inhomogeneity of their silicon material,
the ability of each photosite to convert photons to electrons varies. This
results in some photosites being more or less sensitive to light than they
should be, independent of what is being photographed.
So, even if you used two cameras of the same make and model to snap a
uniformly lit surface – where every point on the surface has the same
brightness – there'd be subtle differences unique to each camera.
Much like snowflakes, no two imaging sensors are alike.
The different sensitivities of the photosites creates a type of
imperceptible image watermark. Although unintentional, it acts like a
fingerprint, unique to your camera’s sensor, which is imprinted onto every
photo you take. Much like snowflakes, no two imaging sensors are alike.
In the digital image forensics community, this sensor fingerprint is known
as "photo response non-uniformity". And it's "difficult to remove even
when one tries", says Jessica Fridrich of Binghamton University in New
York state. It's inherent to the sensor, as opposed to measures, such as
photo metadata, that are "intentionally implemented", she explains.
Fake photos
The upside of the non-uniformity fingerprint technique is that it can help
researchers like Fridrich identify faked images.
In principle, photos constitute a rich reference to the physical world,
and can therefore be used for their evidential value, since they portray
what is. However, in the current climate of disinformation – exacerbated
by the ready supply of image editing software – it has become increasingly
important to know the origin, integrity and nature of digital images.
Fridrich has patented the photo fingerprinting technique, and it has been
officially approved for use as forensic evidence in court cases in the
United States. It means investigators can identify manipulated areas,
associate it with a specific camera device, or establish its processing
history.
Fridrich believes this technology could also be used to reveal AI-
generated synthetic imagery known as deepfakes. And tentative research
corroborates this. The distinguishing feature of a deepfake is its
photorealism. Having gained infamy in 2018, due to their use in
pornographic videos, deepfakes present a tangible threat to the
information ecosystem. If we are unable to differentiate between what is
real and what is not, then all media consumed can be reasonably doubted.
You may also like:
The hidden signs that can reveal a fake photo
The greatest security threat of the post-truth age
The intriguing history of ghost photography
In the post-truth age, the ability to spot fakery is obviously a positive
development. But at the same time such photo-fingerprinting methods can
"have positive and negative uses", says Hany Farid, a professor in
electrical engineering and computer sciences at the University of
California, Berkeley and founder of digital image forensics.
While Farid has used the non-uniformity technique to link photos back to
specific cameras in child sexual abuse cases – a clear benefit – he also
cautions that as "with any identification technology, care should be taken
to make sure that it is not misused". This is particularly pertinent to
individuals such as human rights' activists, photojournalists and whistle-
blowers, whose safety may depend upon their anonymity. According to Farid,
such individuals could be "targeted by linking an image back to their
device or previously posted [online] images".
When considering these privacy issues, we might draw parallels with
another technology. Many colour printers add secret tracking dots to
documents: virtually invisible yellow dots that reveal a printer's serial
number, as well as the date and time a document was printed. In 2017,
these dots may have been used by the FBI in the identification of Reality
Winner as the source of a leaked National Security Agency document, which
detailed alleged Russian interference in the 2016 US presidential
election.
Regardless of your opinion on whistleblowing, these surveillance
techniques could affect us all. The European Commission has voiced
concerns, suggesting that such mechanisms could erode an individual's
"right to privacy and private life". If we view photo fingerprints as
being equivalent to a printer's serial number, then this prompts us to ask
whether photo response non-uniformity also violates an individual's right
to protection of their personal data.
Despite our chronic predisposition to self-disclose over the internet, we
vehemently reserve the right to privacy. In principle, people should be
able to decide the degree to which information about themselves is
communicated externally. But in light of what we now know about forensic
photo tracking, such self-determination may only be an illusion of
control.
Standard metadata is difficult enough to avoid – you have to scrub it
afterwards, and the only piece of information you can stop from being
created in the first instance is photo geolocation. Photo response non-
uniformity, however, is far more difficult to extricate. Technically, it
should be possible to suppress, for example, by reducing the image
resolution, says Farid. But, by how much? This of course depends on many
factors such as the type of device used for image capture, as well as the
fingerprint matching algorithm employed. There is no one-size-fits-all
solution to fingerprint removal.
So, how concerned should we be about photo response non-uniformity from an
ethical standpoint? When I asked Fridrich about the implications of its
various applications, she candidly remarked, "a carpenter can do wonders
with a hammer, but a hammer can also kill". While no one is saying that
the hidden data inside your photos could be deadly, her point is that this
is a technique that could cause harm in the wrong hands.
You don't need to be Donald Trump or John McAfee to be affected by the
rise of photo metadata and fingerprints. So the next time you take a snap
with your smartphone, you might pause to reflect on how much more is being
captured than what you see through the lens.
--
"LOCKDOWN", left-wing COVID fearmongering. 95% of COVID infections
recover with no after effects.
No collusion - Special Counsel Robert Swan Mueller III, March 2019.
Officially made Nancy Pelosi a two-time impeachment loser.
Donald J. Trump, cheated out of a second term by fraudulent "mail-in"
ballots. Report voter fraud: sf.n...@mail.house.gov
Thank you for cleaning up the disaster of the 2008-2017 Obama / Biden
fiasco, President Trump.
Under Barack Obama's leadership, the United States of America became the
The World According To Garp. Obama sold out heterosexuals for Hollywood
queer liberal democrat donors.
President Trump boosted the economy, reduced illegal invasions, appointed
dozens of judges and three SCOTUS justices.
your-photos
They say a picture is worth a thousand words. Actually, there's a great
deal more hidden inside the modern digital image, says researcher Jerone
Andrews.
On 3 October 2020, the White House published two photographs of Donald
Trump, signing papers and reading briefings. The day before, Trump had
announced he had caught the coronavirus and these photos were apparently
released to show that he was in rude health. His daughter Ivanka tweeted
one of the photos with the caption: "Nothing can stop him working for the
American people. RELENTLESS!"
But keen-eyed observers noticed something unusual.
The photos were taken in two different rooms in Walter Reed National
Military Medical Center. In one Trump wears a jacket, in the other just a
shirt. Coupled with public statements about his positive health and work
ethic, the implication was that he had been handling his presidential
duties all day, despite his illness. The photo timestamps, however, said
otherwise. The images were taken 10 minutes apart.
Of course, there are other possible explanations for why they were shot so
closely together. Perhaps the photographer only had access for 10 minutes,
and maybe Trump always intended to switch rooms during that window.
However, the White House can't have been happy that people noticed the
timestamps. It led news outlets and commentators to talk about whether the
images were staged for a photoshoot to project a political message, and to
question whether Trump really was working so "relentlessly" after all.
Hidden information inside digital photos can reveal much more than
photographers and their subjects bargain for
It's not the only time hidden information inside a digital photo has led
to unintended consequences. Just ask John McAfee, founder of the eponymous
antivirus software. In 2012, he was on the run from the Belizean
authorities in Central America. Reporters from Vice magazine tracked him
down and published an image of him online, under the headline "We Are With
John McAfee Right Now, Suckers". Yet without them realising, location data
embedded in the photo inadvertently revealed that McAfee was in Guatemala.
He was soon found, and detained.
These are just two examples of how hidden information inside digital
photos can reveal much more than the photographers and their subjects
bargained for. Could your own photos be sharing more details with the
world than you realise too?
When you take a photo, your smartphone or digital camera stores "metadata"
within the image file. This automatically and parasitically burrows itself
into every photo you take. It is data about data, providing identifying
information such as when and where an image was captured, and what type of
camera was used.
It is not impossible to expunge metadata, using freely available tools
such as ExifTool. But many people don't even realise the data is there,
let alone how it might be used, so they don't bother to do anything about
it before they post images online. Some social media platforms remove
information like geolocation (though only from public view), but many
other websites do not.
This lack of awareness has proven useful for police investigators, to help
them place unwitting criminals at a scene. But it also poses a privacy
problem for law-abiding citizens if the authorities can track their
activities through images on their camera and social media. And
unfortunately, savvy criminals can use the same tricks as the police: if
they can discover where and when a photo was taken, it can leave you
vulnerable to crimes such as burglary or stalking.
But metadata is not the only thing hidden in your photos. There is also a
unique personal identifier linking every image you capture to the specific
camera used, but it's one you'd probably never suspect. Even professional
photographers might not realise or remember that it's there.
To understand what this identifier is, you first have to understand how a
photo is captured. Central to every digital camera, including those inside
smartphones, is its imaging sensor. This is composed of a grid of millions
of silicon "photosites", which are cavities that absorb photons (light).
Due to a phenomenon known as the photoelectric effect, the absorption of
photons causes a photosite to eject electrons a bit like a nightclub
bouncer.
The electrical charge of the electrons emitted from a photosite is
measured and converted into a digital value. This results in a single
value for each photosite, which describes the amount of light detected.
And this is how a photo is formed. Or etymologically speaking, a drawing
with light.
However, due to imperfections in the manufacturing process of imaging
sensors, the dimensions of each photosite differs ever so slightly. And
when coupled with the inherent inhomogeneity of their silicon material,
the ability of each photosite to convert photons to electrons varies. This
results in some photosites being more or less sensitive to light than they
should be, independent of what is being photographed.
So, even if you used two cameras of the same make and model to snap a
uniformly lit surface – where every point on the surface has the same
brightness – there'd be subtle differences unique to each camera.
Much like snowflakes, no two imaging sensors are alike.
The different sensitivities of the photosites creates a type of
imperceptible image watermark. Although unintentional, it acts like a
fingerprint, unique to your camera’s sensor, which is imprinted onto every
photo you take. Much like snowflakes, no two imaging sensors are alike.
In the digital image forensics community, this sensor fingerprint is known
as "photo response non-uniformity". And it's "difficult to remove even
when one tries", says Jessica Fridrich of Binghamton University in New
York state. It's inherent to the sensor, as opposed to measures, such as
photo metadata, that are "intentionally implemented", she explains.
Fake photos
The upside of the non-uniformity fingerprint technique is that it can help
researchers like Fridrich identify faked images.
In principle, photos constitute a rich reference to the physical world,
and can therefore be used for their evidential value, since they portray
what is. However, in the current climate of disinformation – exacerbated
by the ready supply of image editing software – it has become increasingly
important to know the origin, integrity and nature of digital images.
Fridrich has patented the photo fingerprinting technique, and it has been
officially approved for use as forensic evidence in court cases in the
United States. It means investigators can identify manipulated areas,
associate it with a specific camera device, or establish its processing
history.
Fridrich believes this technology could also be used to reveal AI-
generated synthetic imagery known as deepfakes. And tentative research
corroborates this. The distinguishing feature of a deepfake is its
photorealism. Having gained infamy in 2018, due to their use in
pornographic videos, deepfakes present a tangible threat to the
information ecosystem. If we are unable to differentiate between what is
real and what is not, then all media consumed can be reasonably doubted.
You may also like:
The hidden signs that can reveal a fake photo
The greatest security threat of the post-truth age
The intriguing history of ghost photography
In the post-truth age, the ability to spot fakery is obviously a positive
development. But at the same time such photo-fingerprinting methods can
"have positive and negative uses", says Hany Farid, a professor in
electrical engineering and computer sciences at the University of
California, Berkeley and founder of digital image forensics.
While Farid has used the non-uniformity technique to link photos back to
specific cameras in child sexual abuse cases – a clear benefit – he also
cautions that as "with any identification technology, care should be taken
to make sure that it is not misused". This is particularly pertinent to
individuals such as human rights' activists, photojournalists and whistle-
blowers, whose safety may depend upon their anonymity. According to Farid,
such individuals could be "targeted by linking an image back to their
device or previously posted [online] images".
When considering these privacy issues, we might draw parallels with
another technology. Many colour printers add secret tracking dots to
documents: virtually invisible yellow dots that reveal a printer's serial
number, as well as the date and time a document was printed. In 2017,
these dots may have been used by the FBI in the identification of Reality
Winner as the source of a leaked National Security Agency document, which
detailed alleged Russian interference in the 2016 US presidential
election.
Regardless of your opinion on whistleblowing, these surveillance
techniques could affect us all. The European Commission has voiced
concerns, suggesting that such mechanisms could erode an individual's
"right to privacy and private life". If we view photo fingerprints as
being equivalent to a printer's serial number, then this prompts us to ask
whether photo response non-uniformity also violates an individual's right
to protection of their personal data.
Despite our chronic predisposition to self-disclose over the internet, we
vehemently reserve the right to privacy. In principle, people should be
able to decide the degree to which information about themselves is
communicated externally. But in light of what we now know about forensic
photo tracking, such self-determination may only be an illusion of
control.
Standard metadata is difficult enough to avoid – you have to scrub it
afterwards, and the only piece of information you can stop from being
created in the first instance is photo geolocation. Photo response non-
uniformity, however, is far more difficult to extricate. Technically, it
should be possible to suppress, for example, by reducing the image
resolution, says Farid. But, by how much? This of course depends on many
factors such as the type of device used for image capture, as well as the
fingerprint matching algorithm employed. There is no one-size-fits-all
solution to fingerprint removal.
So, how concerned should we be about photo response non-uniformity from an
ethical standpoint? When I asked Fridrich about the implications of its
various applications, she candidly remarked, "a carpenter can do wonders
with a hammer, but a hammer can also kill". While no one is saying that
the hidden data inside your photos could be deadly, her point is that this
is a technique that could cause harm in the wrong hands.
You don't need to be Donald Trump or John McAfee to be affected by the
rise of photo metadata and fingerprints. So the next time you take a snap
with your smartphone, you might pause to reflect on how much more is being
captured than what you see through the lens.
--
"LOCKDOWN", left-wing COVID fearmongering. 95% of COVID infections
recover with no after effects.
No collusion - Special Counsel Robert Swan Mueller III, March 2019.
Officially made Nancy Pelosi a two-time impeachment loser.
Donald J. Trump, cheated out of a second term by fraudulent "mail-in"
ballots. Report voter fraud: sf.n...@mail.house.gov
Thank you for cleaning up the disaster of the 2008-2017 Obama / Biden
fiasco, President Trump.
Under Barack Obama's leadership, the United States of America became the
The World According To Garp. Obama sold out heterosexuals for Hollywood
queer liberal democrat donors.
President Trump boosted the economy, reduced illegal invasions, appointed
dozens of judges and three SCOTUS justices.
Alan Browne
Jul 19, 2021, 12:02:29 PM7/19/21
to
On 2021-07-18 15:03, Leroy N. Soetoro wrote:
> On 3 October 2020, the White House published two photographs of Donald
> Trump, signing papers and reading briefings. The day before, Trump had
> announced he had caught the coronavirus and these photos were apparently
> released to show that he was in rude health. His daughter Ivanka tweeted
> one of the photos with the caption: "Nothing can stop him working for the
> American people. RELENTLESS!"
The WaPo has a good article about Trump's Covid infection and the battle
> On 3 October 2020, the White House published two photographs of Donald
> Trump, signing papers and reading briefings. The day before, Trump had
> announced he had caught the coronavirus and these photos were apparently
> released to show that he was in rude health. His daughter Ivanka tweeted
> one of the photos with the caption: "Nothing can stop him working for the
> American people. RELENTLESS!"
to get him well. He was in dire straits several times.
They threw every treatment possible at him - requiring special
authorization from the FDA for monoclonal antibody treatment. He also
received Remdesivir which has marginal effect.
https://www.washingtonpost.com/politics/2021/06/24/nightmare-scenario-book-excerpt/
--
"...there are many humorous things in this world; among them the white
man's notion that he is less savage than the other savages."
-Samuel Clemens
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