Re: Is it possible to transfer data by using light
Re: Is it possible to transfer data by using light
- Subject: Re: Is it possible to transfer data by using light
- From: Michael David Crawford <email@hidden>
- Date: Fri, 18 Sep 2015 05:35:48 -0700
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
email@hidden
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 <email@hidden> 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 <email@hidden> 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/
>>
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