YouTuber Tom Scott visits the encryption lamps. [3]
Ben Collver <bencollver@tilde.pink> wrote:
"As one might expect, lava lamps are consistently random. The 'lava'
in a lava lamp never takes the same shape twice, and as a result,
observing a group of lava lamps is a great source for random data."
At CloudFare, there is a wall of around 100 lava lamps, which are
running and doing their gloopy thing. At intervals, a camera pointed
at the lamps takes a photo. The random colors of the pixels are then
used to create an encryption key.
That's neat, although I can't help but think of how inefficient it
is compared to most other random data sources, given all the power
that would be required by 100 lava lamps. Various other common
enthropy sources would use less power than the camera filming them.
Clearly a gimmick. Still I'll admit that if someone else was
paying the power bill, I'd love nothing more than to have a job
building something like that. :)
The Cloudflare page also goes on to describe other novel methods
that they use at other offices, which are less audaciously
power-hungry:
"The other two main Cloudflare offices are in London and Singapore,
and each office has its own method for generating random data from
real-world inputs. London takes photos of a double-pendulum system
mounted in the office (a pendulum connected to a pendulum, the
movements of which are mathematically unpredictable). The Singapore
office measures the radioactive decay of a pellet of uranium (a
small enough amount to be harmless)."
"As one might expect, lava lamps are consistently random. The 'lava'
in a lava lamp never takes the same shape twice, and as a result,
observing a group of lava lamps is a great source for random data."
At CloudFare, there is a wall of around 100 lava lamps, which are
running and doing their gloopy thing. At intervals, a camera pointed
at the lamps takes a photo. The random colors of the pixels are then
used to create an encryption key.
[4]
<https://www.cloudflare.com/en-gb/learning/ssl/lava-lamp-encryption/>
I wish Cloudflare would learn that no amount of cute enthropy
sourcing can compensate for the frustration of that link going to
an almost blank page that tells me:
"Enable JavaScript and cookies to continue"
Ben Collver <bencollver@tilde.pink> wrote:
"As one might expect, lava lamps are consistently random. The 'lava'
in a lava lamp never takes the same shape twice, and as a result,
observing a group of lava lamps is a great source for random data."
At CloudFare, there is a wall of around 100 lava lamps, which are
running and doing their gloopy thing. At intervals, a camera pointed
at the lamps takes a photo. The random colors of the pixels are then
used to create an encryption key.
That's neat, although I can't help but think of how inefficient it
is compared to most other random data sources, given all the power
that would be required by 100 lava lamps. Various other common
enthropy sources would use less power than the camera filming them.
Clearly a gimmick. Still I'll admit that if someone else was
paying the power bill, I'd love nothing more than to have a job
building something like that. :)
I wish Cloudflare would learn that no amount of cute enthropy
sourcing can compensate for the frustration of that link going to
an almost blank page that tells me:
"Enable JavaScript and cookies to continue"
not@telling.you.invalid (Computer Nerd Kev) writes:
Ben Collver <bencollver@tilde.pink> wrote:
"As one might expect, lava lamps are consistently random. The 'lava'
in a lava lamp never takes the same shape twice, and as a result,
observing a group of lava lamps is a great source for random data."
At CloudFare, there is a wall of around 100 lava lamps, which are
running and doing their gloopy thing. At intervals, a camera pointed
at the lamps takes a photo. The random colors of the pixels are then
used to create an encryption key.
That's neat, although I can't help but think of how inefficient it
is compared to most other random data sources, given all the power
that would be required by 100 lava lamps. Various other common
enthropy sources would use less power than the camera filming them.
Clearly a gimmick. Still I'll admit that if someone else was
paying the power bill, I'd love nothing more than to have a job
building something like that. :)
I had a go at extracting random numbers from a lightening globe -- yew
kno, glass globe that generates a lightening-like electrical display wandering randomly around the inside surface. Put the globe in front
of a web cam, played with the image data. Never managed to figure out
how to get reliably random numbers from it. Maybe I needed a whole
wall of them? :-o
Jan van den Broek <balglaas@dds.nl> writes:
2023-10-27, Mike Spencer <mds@bogus.nodomain.nowhere> schrieb:
I had a go at extracting random numbers from a lightening globe -- yew
kno, glass globe that generates a lightening-like electrical display
wandering randomly around the inside surface. Put the globe in front
of a web cam, played with the image data. Never managed to figure out
how to get reliably random numbers from it. Maybe I needed a whole
wall of them? :-o
I have a very cheap webcam, I take a picture and use a hash of that.
I didn't think of that. I've done some reading but don't know enough
about the math to understand clearly that the/a/whatever hashing
algorithm that is (more or less) guaranteed to produce a unique
irreversible hash of its input will also produce a bit stream meeting
crypto standards for "random".
Along the same line, I don't understand why you can't (or can?)
produce a random bit stream by running a hash algorithm on whatever
files chosen by personal whim from your HD (or any arbitrary source)
and stringing the output bits together. I infer that such a technique
must have weaknesses or I would have heard about getting crypto random numbers that way.
2023-10-27, Mike Spencer <mds@bogus.nodomain.nowhere> schrieb:
I had a go at extracting random numbers from a lightening globe -- yew
kno, glass globe that generates a lightening-like electrical display
wandering randomly around the inside surface. Put the globe in front
of a web cam, played with the image data. Never managed to figure out
how to get reliably random numbers from it. Maybe I needed a whole
wall of them? :-o
I have a very cheap webcam, I take a picture and use a hash of that.
Jan van den Broek <balglaas@dds.nl> writes:
2023-10-27, Mike Spencer <mds@bogus.nodomain.nowhere> schrieb:
I had a go at extracting random numbers from a lightening globe --
yew kno, glass globe that generates a lightening-like electrical
display wandering randomly around the inside surface. Put the globe
in front of a web cam, played with the image data. Never managed to
figure out how to get reliably random numbers from it. Maybe I
needed a whole wall of them? :-o
I have a very cheap webcam, I take a picture and use a hash of that.
I didn't think of that. I've done some reading but don't know enough
about the math to understand clearly that the/a/whatever hashing
algorithm that is (more or less) guaranteed to produce a unique
irreversible hash of its input will also produce a bit stream meeting
crypto standards for "random".
Along the same line, I don't understand why you can't (or can?)
produce a random bit stream by running a hash algorithm on whatever
files chosen by personal whim from your HD (or any arbitrary source)
and stringing the output bits together. I infer that such a technique
must have weaknesses or I would have heard about getting crypto random numbers that way.
On 2023-10-26, Computer Nerd Kev <not@telling.you.invalid> wrote:
I wish Cloudflare would learn that no amount of cute enthropy
sourcing can compensate for the frustration of that link going to
an almost blank page that tells me:
"Enable JavaScript and cookies to continue"
Hear hear! It is a major source of frustration for users of a
certain Linux forum that i read, where the admins have chosen to
use Clownflare for DDoS protection.
In article <slrnujnohk.2j9.bencollver@svadhyaya.localdomain>,
Ben Collver <bencollver@tilde.pink> wrote:
On 2023-10-26, Computer Nerd Kev <not@telling.you.invalid> wrote:
I wish Cloudflare would learn that no amount of cute enthropy
sourcing can compensate for the frustration of that link going to
an almost blank page that tells me:
"Enable JavaScript and cookies to continue"
Hear hear! It is a major source of frustration for users of a
certain Linux forum that i read, where the admins have chosen to
use Clownflare for DDoS protection.
I have never encountered this or found it to be a problem with a browser, seeing that most sites today seem to require javascript and cookies for any function at all anyway.
In article <slrnujnohk.2j9.bencollver@svadhyaya.localdomain>,
Ben Collver <bencollver@tilde.pink> wrote:
On 2023-10-26, Computer Nerd Kev <not@telling.you.invalid> wrote:
"Enable JavaScript and cookies to continue"
Hear hear! It is a major source of frustration for users of a
certain Linux forum that i read, where the admins have chosen to
use Clownflare for DDoS protection.
I have never encountered this or found it to be a problem with a browser, seeing that most sites today seem to require javascript and cookies for any function at all anyway.
But of course cloudflare often breaks wget which is an issue.
Mike Spencer <mds@bogus.nodomain.nowhere> writes:
I didn't think of that. I've done some reading but don't know enough
about the math to understand clearly that the/a/whatever hashing
algorithm that is (more or less) guaranteed to produce a unique irreversible hash of its input will also produce a bit stream meeting crypto standards for "random".
No hashing algorithm is guaranteed to produce unique outputs. That would
be impossible since there are overwhelmingly more possible inputs than outputs.
Along the same line, I don't understand why you can't (or can?)
produce a random bit stream by running a hash algorithm on whatever
files chosen by personal whim from your HD (or any arbitrary source)
and stringing the output bits together. I infer that such a technique
must have weaknesses or I would have heard about getting crypto random numbers that way.
In concrete terms an attacker who could recover the contents of your
hard disk (in a later data breach, or with a warrant, etc) would only
have to calculate the hash of each file on your disk in order to predict
the possible outputs from your RNG - unlikely to be more than a few
billion operations.
In contrast with a proper RNG the attacker has no better option than exhaustive search.
Richard Kettlewell <invalid@invalid.invalid> wrote:
Mike Spencer <mds@bogus.nodomain.nowhere> writes:
I didn't think of that. I've done some reading but don't know
enough about the math to understand clearly that the/a/whatever
hashing algorithm that is (more or less) guaranteed to produce a
unique irreversible hash of its input will also produce a bit stream
meeting crypto standards for "random".
No hashing algorithm is guaranteed to produce unique outputs. That would
be impossible since there are overwhelmingly more possible inputs than
outputs.
Depends what "unique" means. If it means a 1-1 function from inputs to outputs then it would be impossible for the reason you mention. If it means an output never encountered before in the history of mankind and extremely unlikely to ever be encountered again then we are in fact hoping that cryptographic hashing algorithms achieve this.
I think the technique proposed is to randomly ("whim") choose a subset
of your files and then combine the output bits in some order. So the
final output would depend on both which subset of your files you chose
and in which order you combined them. If you have say 1000 files then
there are 2**1000 possible subsets and , if you chose N files , there
are N! different orders you can put them in. It's not possible to do
an exhaustive search on that.
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