| 摘要 |
<p>Methods and systems for a user to receive location-based services for user selected locations while maintaining the privacy of his/her location unless in the vicinity of a user selected location. A user designates selected locations to the LBS provider. The LBS provider digitally signs grid cell identifiers of approved locations and the signatures are stored in the user's mobile device. The mobile device determines the grid cell identifier of its current location, blinds the grid cell identifier, and sends the blinded grid cell identifier to the LBS provider. The LBS provider digitally signs the blinded grid cell identifier, and returns the signature to the mobile device. The mobile device removes the blinding from the blinded signature to obtain the digital signature for the grid cell identifier. The user's mobile device then compares the signature of the grid cell identifier with those stored in its memory to determine whether the user is near any approved locations.</p> |
