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Slacker007 wrote: but the algorithm...you don't know.
as you've described, it's:
1. get an image from a stream.
2. use its dimensions as the seed to a random number generator.
so i need to find:
1. your stream (sniff your IP traffic)
2. which random number generator you're using. (try all the common random number generators)
Slacker007 wrote: the image I grab is the next one in the cue, whether it is your image or 500K others.
if i want control bad enough, all of them will be my images. and you won't know it.
but, your scheme already depends on you having a random number generator. so, if you don't trust rand(time()), get a better RNG. that's much easier than creating a machine to generate random seeds.
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all great points but how would you know what my random number is, this second? You are assuming that you have control over everything I see and do. Have you ever seen an image dump, such as 4chan?
How would you control that?
Just along for the ride.
"the meat from that butcher is just the dogs danglies, absolutely amazing cuts of beef." - DaveAuld (2011)
"No, that is just the earthly manifestation of the Great God Retardon." - Nagy Vilmos (2011)
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Slacker007 wrote: all great points but how would you know what my random number is, this second?
maybe i can't. but if there's no way i can know it, you might not need a super-complex cryptographically-secure RNG. no need to protect yourself from something that's impossible, after all.
so, i've been assuming i can know it.
Slacker007 wrote: You are assuming that you have control over everything I see and do. Have you ever seen an image dump, such as 4chan?
sure. but what if i redirect your IP traffic to my own servers when you pull your images ?
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Chris Losinger wrote: but what if i redirect your HTTP requests to my own servers when you pull your images ?
I'm not a web dev but I'm sure there would be a tell that I could right code for to handle this. The second you redirect, my system goes dark and locks up. Just a thought.
Just along for the ride.
"the meat from that butcher is just the dogs danglies, absolutely amazing cuts of beef." - DaveAuld (2011)
"No, that is just the earthly manifestation of the Great God Retardon." - Nagy Vilmos (2011)
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Slacker007 wrote: but the algorithm...you don't know.
A key point of the strongest algorithms out there is that the way they work is immaterial. The strength, and security, is in the randomness of the source. Any two people picking the same image must, by definition, be generating the same key.
BTW how will your Bob know which image you are using to generate the key?
Panic, Chaos, Destruction. My work here is done.
Drink. Get drunk. Fall over - P O'H
OK, I will win to day or my name isn't Ethel Crudacre! - DD Ethel Crudacre
I cannot live by bread alone. Bacon and ketchup are needed as well. - Trollslayer
Have a bit more patience with newbies. Of course some of them act dumb - they're often *students*, for heaven's sake - Terry Pratchett
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Nagy Vilmos wrote: Any two people picking the same image must, by definition, be generating the same key.
No two people would ever pick the same image. You would have no idea what image I am grabbing because, I don't even know the image I am grabbing. Do see my replys about image dumps such as 4chan.
The randomness of the images is based on the natural random selection process of the internet. I feel that the internet has become as random as nature itself. Out there, I know, but thoughts that this old mind thinks about from time to time.
Just along for the ride.
"the meat from that butcher is just the dogs danglies, absolutely amazing cuts of beef." - DaveAuld (2011)
"No, that is just the earthly manifestation of the Great God Retardon." - Nagy Vilmos (2011)
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Except you wouldn't need images as quickly as numbers... So the "random number generator" for the images could be six interns in a dark basement surfing the web...
Uh, just don't show your boss which images are being scanned...
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Ian Shlasko wrote: six interns in a dark basement surfing the web
people are never random. those interns would show patterns, preferences. even better, they could be replaced by people who would choose specific images.
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Then put privacy screens between them, avert your eyes, and... uh... make sure the algorithm can capture video frames too 
Oh, and hash in the exact time the image was downloaded, and have each of the computers be slightly out of sync.
I'd like to see someone try to duplicate THAT!
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Chris Losinger wrote: people are never random. those interns would show patterns, preferences. even better, they could be replaced by people who would choose specific images.
very true. people, by nature, are predictable.
Just along for the ride.
"the meat from that butcher is just the dogs danglies, absolutely amazing cuts of beef." - DaveAuld (2011)
"No, that is just the earthly manifestation of the Great God Retardon." - Nagy Vilmos (2011)
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Oh boys, that seems a bad idea like only seasoned VBers could come up with.
There are a couple of very popular image sizes, e.g. built in in pocket camera's. For one, the size often is a multiple of 100, why would you restrict your RNG seed values to that?
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Luc Pattyn wrote: that seems a bad idea like only seasoned VBers could come up with.
Luc, are you saying that I am a seasoned VBer?  
Luc Pattyn wrote: There are a couple of very popular image sizes, e.g. built in in pocket camera's. For one, the size often is a multiple of 100, why would you restrict your RNG seed values to that?
yea. true. AspDotNetDev made a good point too. I am not a great computer scientist after all.
:hangs_head_in_shame:
Just along for the ride.
"the meat from that butcher is just the dogs danglies, absolutely amazing cuts of beef." - DaveAuld (2011)
"No, that is just the earthly manifestation of the Great God Retardon." - Nagy Vilmos (2011)
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I suspect this has been posted before (in fact I'm sure it has) but it is relevant: Random Number[^]
Ideological Purity is no substitute for being able to stick your thumb down a pipe to stop the water
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Just along for the ride.
"the meat from that butcher is just the dogs danglies, absolutely amazing cuts of beef." - DaveAuld (2011)
"No, that is just the earthly manifestation of the Great God Retardon." - Nagy Vilmos (2011)
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OriginalGriff wrote: I suspect this has been posted before (in fact I'm sure it has) but it is relevant
heheh I love how the entire CP lounge is now walking on eggshells so as not to get crucified for a repost... 
"... having only that moment finished a vigorous game of Wiff-Waff and eaten a tartiflet." - Henry Minute
"...who gives a tinker's cuss?" - Dalek Dave
"Let's face it, after Monday and Tuesday, even the calendar says WTF!" - gavindon
It's plain that they do not yet know what true fear really is. - JSOP 2011
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Twice a day - it's getting out of hand.
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It's not to far off. Moren random generators used for cryptography accumulate "randomness" from a variety of sources, and are rather resilent against injection of non-random data.
For diving into a confusingly fascinating read, see maybe start here[^].
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yeah but there are so many warnings and tags for this article that question it's origins, purpose, and authenticity that I have to suspect it completely.
Just along for the ride.
"the meat from that butcher is just the dogs danglies, absolutely amazing cuts of beef." - DaveAuld (2011)
"No, that is just the earthly manifestation of the Great God Retardon." - Nagy Vilmos (2011)
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You could also search for "random accumulator" or "entropy accumulator".
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Slacker007 wrote: I would "think", that if the images were gathered...at random
So you generate a random number based on gathering images randomly from some source.
Do you see any circles there?
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jschell wrote: Do you see any circles there?
do you because I don't.
The images are random by nature. I don't create the randomness in that, the internet does. I use that natural randomness of the images to seed my random number. The only thing I am creating is the final random number.
Just along for the ride.
"the meat from that butcher is just the dogs danglies, absolutely amazing cuts of beef." - DaveAuld (2011)
"No, that is just the earthly manifestation of the Great God Retardon." - Nagy Vilmos (2011)
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You seem to assume that the randomness of the content of pictures from the internet in general makes your specific pick somehow random. It doesn't! Unless you use some kind of random element, you will pick a very specific picture from a very specific URL, and every other person doing the same will get exactly the same image if following that algorithm. The only random element here is the point in time that you choose to select and download that picture (and even that will only make a difference if you're talking about some image feed channel like you mentioned).
So, in the end, you've based your random number on the current time, just like everyone else!
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Actually, no.
If you have ever been on 4Chan then you would understand what I am talking about. You also need to know that there is no way for you to grab the image at the same time I am because you have no idea when I'm grabbing it.
Images on 4Chan come and go (get moved or deleted) every second. If you don't know when I am going to grab that image, then you have no idea what my seed value was or is.
Just along for the ride.
"the meat from that butcher is just the dogs danglies, absolutely amazing cuts of beef." - DaveAuld (2011)
"No, that is just the earthly manifestation of the Great God Retardon." - Nagy Vilmos (2011)
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You didn't get my meaning - my point was not whether I know or not when you're grabbing it, but that the only random component in your 'algorithm' is exactly that: when you're grabbing it. And that's a time stamp. So you can just as well use that time stamp as your seed.
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I'm not using time at all. I am using the image properties. I don't care about the time. It is not even part of the equation. I would never use time to seed a rng.
Just along for the ride.
"the meat from that butcher is just the dogs danglies, absolutely amazing cuts of beef." - DaveAuld (2011)
"No, that is just the earthly manifestation of the Great God Retardon." - Nagy Vilmos (2011)
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