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How is that any more trustworthy? You can probably use the same source the server would use to verify that information. Not to mention, most phones may not ha

by itake 10y ago

How is that any more trustworthy? You can probably use the same source the server would use to verify that information. Not to mention, most phones may not have those sensors.

ChuckMcM 10y ago
Some very popular phones have a barometer[1]. If you are getting data from a bunch of phones, and most of them are legit, then you'll have a good idea of where the air pressure 'should' be, and if you get a barometer reading that is outside that data set by a standard deviation you can probably 'guess' that it is not coming from a phone at the same lat/lon as the other ones. [1] https://www.phonegg.com/list/303-Cell-Phones-with-Barometer https://www.phonegg.com/list/303-Cell-Phones-with-Barometer
- komali2 10y ago
  So users on phones without barometers cannot use your app, and you are decidedly mobile-only, forever.
  - ChuckMcM 10y ago
    Not at all, the question was how to combat or at least estimate fraudulent 'adjustment' of the karma in a location based service. The way to do that is to take information that is specific to the location, and changes, and provide that data in the input stream to help understand where your clicks/votes are coming from. If one in 5 phones has a barometer with a high degree of probability, then you can use set bounds on the likelyhood that all 5 votes came from legitimate users. It won't be perfect but it will make it harder for scammers to scam without being there.
    - disgruntledphd2 10y ago
      This is a really clever idea. Do you have sources of information about what sensors are present in which phones?
- djrogers 10y ago
  That only adds one extra step to spoofing - now I have to check weather.com for the barometer reading in the location I plan to poof before sending. NBD... Also, pressure in vs outside can vary more than you'd think...
  - ChuckMcM 10y ago
    As with anything, it can be over come at a cost, and the only thing anyone can hope for is to keep the cost of defrauding a system higher than the expected return of successfully defrauding it.

by itake 10y ago

How is that any more trustworthy? You can probably use the same source the server would use to verify that information. Not to mention, most phones may not have those sensors.

ChuckMcM 10y ago

Some very popular phones have a barometer[1]. If you are getting data from a bunch of phones, and most of them are legit, then you'll have a good idea of where the air pressure 'should' be, and if you get a barometer reading that is outside that data set by a standard deviation you can probably 'guess' that it is not coming from a phone at the same lat/lon as the other ones. [1] https://www.phonegg.com/list/303-Cell-Phones-with-Barometer https://www.phonegg.com/list/303-Cell-Phones-with-Barometer

komali2 10y ago
So users on phones without barometers cannot use your app, and you are decidedly mobile-only, forever.
- ChuckMcM 10y ago
  Not at all, the question was how to combat or at least estimate fraudulent 'adjustment' of the karma in a location based service. The way to do that is to take information that is specific to the location, and changes, and provide that data in the input stream to help understand where your clicks/votes are coming from. If one in 5 phones has a barometer with a high degree of probability, then you can use set bounds on the likelyhood that all 5 votes came from legitimate users. It won't be perfect but it will make it harder for scammers to scam without being there.
  - disgruntledphd2 10y ago
    This is a really clever idea. Do you have sources of information about what sensors are present in which phones?
djrogers 10y ago
That only adds one extra step to spoofing - now I have to check weather.com for the barometer reading in the location I plan to poof before sending. NBD... Also, pressure in vs outside can vary more than you'd think...
- ChuckMcM 10y ago
  As with anything, it can be over come at a cost, and the only thing anyone can hope for is to keep the cost of defrauding a system higher than the expected return of successfully defrauding it.