What, pray, is "SHA3 key generation"
That they're using SHA3 as a key generation function to convert a passphrase to a key for encryption? What else would it mean?
DarkJPEG
11–20 of 27 posts
Re: DarkJPEG
#12Earlier quoted context omitted.
Well it's got to be super sekrit so it needs the best SHA algorithm, what better than the one that even the NSA hasn't picked yet? :-)
Oh I'm sure the NSA has already picked it ;) NIST just hasn't yet...
Keccak was picked by NIST last October as the winner of the SHA-3 competition.
Re: DarkJPEG
#13What, pray, is "SHA3 key generation"
init(SHA3(pass + s));
https://github.com/darkjpeg/darkjpeg.github.io/blob/07171bd0...
Re: DarkJPEG
#14No one's worried about the entire concept? It seems a little counter-intuitive to tell someone else your secrets, so they can hide them.
Re: DarkJPEG
#15What, pray, is "SHA3 key generation"
init(SHA3(pass + s)); https://github.com/darkjpeg/darkjpeg.github.io/blob/07171bd0...
That's worrisome; they should be using a purpose-built key derivation function, like PBKDF2, bcrypt or scrypt. Using only SHA3 means it is easy to brute-force the key by searching for likely passwords.
Re: DarkJPEG
#16I don't click on dodgy links.
Re: DarkJPEG
#17is there any evidence that the steganography here is undetectable? i would have thought that uniformly random data in the low bits of an image's data (pixels or fourier coefficients or whatever) was a clear signature for anyone trying to find these things. aren't they naturally correlated in various ways? also, something like tineye can be used to retrieve web-sourced images for comparison, which would make any hidde…
also, something like tineye can be used to retrieve web-sourced images for comparison, which would make any hidden data really obvious (and a smooth gradient would be even more suspicious if the lowest bits weren't smooth).
Smooth gradients are only smooth if you add noise to the lower bits, due to having only 256 color levels per channel. A comparison: http://imgur.com/0cJWm8t
Those color bands are indeed only one color value apart per channel; the first visible band is rgb(50, 120, 50), while the second is rgb(51, 119, 51).
Re: DarkJPEG
#18No one's worried about the entire concept? It seems a little counter-intuitive to tell someone else your secrets, so they can hide them.
I would argue that to most people who download the tor browser that is effectively what they are doing.
As has been shown before, open and closed source products people use (including security software) has been time and time again proven to be insecure.
I still would be somewhat wary to use this site for actual stuff I care about, but its a cool site and a cool little idea.
Re: DarkJPEG
#19is there any evidence that the steganography here is undetectable? i would have thought that uniformly random data in the low bits of an image's data (pixels or fourier coefficients or whatever) was a clear signature for anyone trying to find these things. aren't they naturally correlated in various ways? also, something like tineye can be used to retrieve web-sourced images for comparison, which would make any hidde…
Off course before you even get to all that, I'd be concerned about the steganographic problem where they go to your ISP's logs and see you've visited the site.
That is the first thing I thought.
Unless it runs on your computer and you can trust that, it's useless.
Re: DarkJPEG
#20> Supported container types: [...] rand, which downloads a random image from Wikimedia;
I honestly don't see the point of that container type. How much useful is steganography if the original JPEG is publicly available for comparison? How could anyone ever plausibly deny that?
"You were emailing this image from Wikimedia, but made subtle modifications to the file. Can you explain this?" - "Umm ... I guess I downloaded it via a noisy internet connection." ?!