bpmod wrote:Now to think of another way to obfuscate a QR code.
Brian
Do you want to change what it says, or make it unreadable? I know that the large squares in or near the corners help the code reader figure out which way it's oriented. Also, there's a row of alternating blacks and whites between the bottom-most lines of the two top squares, and a column of them between the right-most lines of the two left squares. I don't know what those do (the Wikipedia article says "timing," but I'm not sure what that refers to), but altering those might go a long way toward creating an unreadable QR code that still looks like one (and can be repaired with a little work by someone aware of the patterns).
I want to make it readable, but as gibberish, while keeping it readable another way to provide the correct output. I guess the whole reason for the various control codes within the QR code is so that it can be read only one way.
Brian
...but the senator, while insisting he was not intoxicated, could not explain his nudity.
If I had 50 cents for every math question I got right, I'd have $6.30 by now.
seaborgium wrote:I don't know what those do (the Wikipedia article says "timing," but I'm not sure what that refers to)
Timing in relation to printed codes generally has to do with positioning/location, so that the reader correctly interprets what it thinks it's reading. For example: all the marks on the side of a Scantron are timing marks, as are the lines at the beginning and end of a UPC code.
bpmod wrote:
I want to make it readable, but as gibberish, while keeping it readable another way to provide the correct output. I guess the whole reason for the various control codes within the QR code is so that it can be read only one way.
Brian
Ahh, I think I know what you're getting at.
Basically, you want to have what visually looks like a QR code with its three tell-tale alignment blocks, but in the main data portion, use a different matrix algorithm, like Data Matrix ( http://en.wikipedia.org/wiki/Data_Matrix ).
bpmod wrote:
I want to make it readable, but as gibberish, while keeping it readable another way to provide the correct output. I guess the whole reason for the various control codes within the QR code is so that it can be read only one way.
Brian
Ahh, I think I know what you're getting at.
Basically, you want to have what visually looks like a QR code with its three tell-tale alignment blocks, but in the main data portion, use a different matrix algorithm, like Data Matrix ( http://en.wikipedia.org/wiki/Data_Matrix ).
Sort of. But even simpler.
In my example above, I have modified a valid QR code in one very simple way. Anybody can put it back with very little effort and no special (hardware/software) tools. It cannot be read by a reader (without knowing how it was altered), as it does not appear to be a valid QR code. (That is, to the reader... the naked eye sees it as a valid QR code.)
What I had been hoping is that, instead of the reader simply dismissing it as invalid, it would read, but output gibberish. My intent was to have anybody reading it come to the conclusion that the content was scrambled before the QR code was created from it. Or simply that the content is supposed to be gibberish.
Security through obfuscation.
Brian
...but the senator, while insisting he was not intoxicated, could not explain his nudity.
If I had 50 cents for every math question I got right, I'd have $6.30 by now.
bpmod wrote:
I want to make it readable, but as gibberish, while keeping it readable another way to provide the correct output. I guess the whole reason for the various control codes within the QR code is so that it can be read only one way.
Brian
Ahh, I think I know what you're getting at.
Basically, you want to have what visually looks like a QR code with its three tell-tale alignment blocks, but in the main data portion, use a different matrix algorithm, like Data Matrix ( http://en.wikipedia.org/wiki/Data_Matrix ).
Sort of. But even simpler.
In my example above, I have modified a valid QR code in one very simple way. Anybody can put it back with very little effort and no special (hardware/software) tools. It cannot be read by a reader (without knowing how it was altered), as it does not appear to be a valid QR code. (That is, to the reader... the naked eye sees it as a valid QR code.)
What I had been hoping is that, instead of the reader simply dismissing it as invalid, it would read, but output gibberish. My intent was to have anybody reading it come to the conclusion that the content was scrambled before the QR code was created from it. Or simply that the content is supposed to be gibberish.
Security through obfuscation.
Brian
Checksums are harsh mistresses.
The only way, I'd imagine, to have a QR code return gibberish is to make it valid gibberish.
jeff6286 wrote:
If I look at that long enough, and tilt my head just right, I think I can see a spaceship. Is that right, is it a spaceship?
I see the dragon from Tic Tac Dough
A bulldog?
It's a schooner!
On a serious note, I wouldn't know where to begin. I would guess it'd have to start with decoding what's there by hand as all the basic features don't appear tampered with...but even there I'm at a loss.
I am a little ashamed to admit that my six-year-old self was scared s---less by that stupid dragon. No likey.
I had completely forgotten about it until this mention. I was a bit older than six, though, so I don't think I had any trauma as a result of it back then.
Brian
...but the senator, while insisting he was not intoxicated, could not explain his nudity.
If I had 50 cents for every math question I got right, I'd have $6.30 by now.
I am a little ashamed to admit that my six-year-old self was scared s---less by that stupid dragon. No likey.
I had completely forgotten about it until this mention. I was a bit older than six, though, so I don't think I had any trauma as a result of it back then.
Brian
I grew up with the 1990 revival of Tic Tac Dough, so I had a rapping dragon and dragonslayer, and Mr. YOU WIIIIIIIIIIIIIIN!!!!!!!! himself, Patrick Wayne.