On Sun, Sep 20, 2015 at 9:55 PM, Jens Alfke <j...@mooseyard.com> wrote:
> But honestly, if you're going this route, it will be much faster to > transmit QR codes, since each code contains thousands of bits. > Especially given that recent versions of iOS can detect and decode QR codes automatically, much like face detection. https://developer.apple.com/library/ios/documentation/AVFoundation/Reference/AVMetadataMachineReadableCodeObject_Class/index.html https://developer.apple.com/library/ios/documentation/QuartzCore/Reference/CIQRCodeFeature/ > On Sep 20, 2015, at 7:21 PM, ico <jche...@gmail.com> wrote: > > > > After reading all of the replies, no one mentioned how to use iPhone to > > detect the light changes (bright and dark) in codes, I just have no clue > > how to make it works as long as I remember developers have no right to > > access the light sensor, so I guess we have to use camera to achieve > this, > > but I just don't know how. Can anyone point me to something to read so I > > can start digging into this and make the whole thing start to work? > > > > Thank you all. > > > > On Fri, 18 Sep 2015 at 20:38 Michael David Crawford < > mdcrawf...@gmail.com> > > wrote: > > > >> Do iOS devices support Trusted Computing in hardware? If so is it > >> accessible to userspace apps? > >> > >> If so, you could store your phones secret in a write-only register. > >> For the profoundly paranoid, even the duplication of your storage > >> would not yield your phone's secret, The Bad Guy would need your > >> personal phone. > >> > >> Modern Macs - to the best of my knowledge - provide trusted computing > >> chips, on can access them from userspace with a modest bit of code. > >> Michael David Crawford P.E., Consulting Process Architect > >> mdcrawf...@gmail.com > >> http://mike.soggywizard.com/ > >> > >> One Must Not Trifle With Wizards For It Makes Us Soggy And Hard To > >> Light. > >> > >> > >>> On Fri, Sep 18, 2015 at 3:12 AM, Maxthon Chan <m...@maxchan.info> > wrote: > >>> The "over-the-shoulder" issue can be avoided using what is effectively > a > >> Diffie-Hellman on top of QR codes. This can be done using front-facing > >> cameras on two devices placed face-to-face. > >>> > >>> Sent from my iPhone > >>> > >>>> On Sep 18, 2015, at 00:46, Pascal J. Bourguignon < > p...@informatimago.com> > >> wrote: > >>>> > >>>> > >>>> > >>>>> On 17/09/15 17:32, Michael David Crawford wrote: > >>>>> And what the man said: I myself experience seizures in which I lose > >>>>> consciousness for as long as three weeks. Before they were diagnosed > >>>>> I would experience seizures while driving my car then suddenly find > >>>>> myself in unfamiliar places without any clue how I got there. > >>>>> > >>>>> I don't know for sure but strongly suspect that modern computer user > >>>>> interfaces caused my seizure disorder as well as that of my cousin. > >>>>> Seizures are not otherwise found among any of our blood relatives. > >>>> > >>>> But then if you don't use the whole screen, but only the area that > >>>> should be in front of the camera of the superposed phone, then users > >>>> shouldn't be subjected to much stroboscopic light. > >>>> > >>>> Having the objective so close from the light source does not allow > >>>> the camera to distinguish pixels; for example, a black to white > >>>> transition takes about 1/10 of the height of the camera view. > >>>> But this means that you might still able to transmit about ten pixels > >> at once, > >>>> and you can multiply that by a number of color that you can detect > >> reliably > >>>> being that out of focus. Basically, I would expect 8 colors to be > >> clearly > >>>> distinguishable. Actually, probably more colors should be > >> distinguishable, > >>>> if you can filter out the interferences due to the grid of the camera > >> vs. > >>>> the grid of the screen. So assume 4 bits for the color, and 9 areas, > >>>> that's 36 bit/moment, and you should be able to do 30 moment/second, > >>>> for a total of 1080 bit/second. A little less for ECC, about 1 KB/s > >>>> is not too bad. It's good enough to transmit a good private key, and > >> then > >>>> transfer the data thru wifi. > >>>> > >>>> > >>>> Of course, if you move the camera out to focus on the screen, then > >>>> you can transmit at a higher speed things like QR codes, but they > >>>> could also be seen over the shoulder by high resolution cameras. > >>>> > >>>> -- > >>>> __Pascal J. Bourguignon__ > >>>> http://www.informatimago.com/ > >>>> > >>>> _______________________________________________ > >>>> > >>>> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > >>>> > >>>> Please do not post admin requests or moderator comments to the list. > >>>> Contact the moderators at cocoa-dev-admins(at)lists.apple.com > >>>> > >>>> Help/Unsubscribe/Update your Subscription: > >>>> https://lists.apple.com/mailman/options/cocoa-dev/max%40maxchan.info > >>>> > >>>> This email sent to m...@maxchan.info > >>> > >>> _______________________________________________ > >>> > >>> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > >>> > >>> Please do not post admin requests or moderator comments to the list. > >>> Contact the moderators at cocoa-dev-admins(at)lists.apple.com > >>> > >>> Help/Unsubscribe/Update your Subscription: > >>> > https://lists.apple.com/mailman/options/cocoa-dev/mdcrawford%40gmail.com > >>> > >>> This email sent to mdcrawf...@gmail.com > >> _______________________________________________ > >> > >> Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > >> > >> Please do not post admin requests or moderator comments to the list. > >> Contact the moderators at cocoa-dev-admins(at)lists.apple.com > >> > >> Help/Unsubscribe/Update your Subscription: > >> https://lists.apple.com/mailman/options/cocoa-dev/jche128%40gmail.com > >> > >> This email sent to jche...@gmail.com > > _______________________________________________ > > > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > > > Please do not post admin requests or moderator comments to the list. > > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > > > Help/Unsubscribe/Update your Subscription: > > https://lists.apple.com/mailman/options/cocoa-dev/jens%40mooseyard.com > > > > This email sent to j...@mooseyard.com > > _______________________________________________ > > Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) > > Please do not post admin requests or moderator comments to the list. > Contact the moderators at cocoa-dev-admins(at)lists.apple.com > > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/cocoa-dev/himself%40sfko.com > > This email sent to hims...@sfko.com > _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. 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