Traditional pay-and-display ticket machines are currently coexisting, but will probably be replaced in the near future, with pay-by-phone applications. Such applications facilitate the payment for parking in regulated areas. Companies providing this service collect and manage information about all the parking transactions performed by drivers. That information is very sensitive and can be used to generate reports on the parking history of drivers, posing a threat on their privacy. This paper proposes a pay-by-phone parking system in which the service provider is prevented from being able to track the parking transactions of drivers. The new proposal requires drivers to be connected only at the beginning of a parking transaction, or at the moment of indicating that a parking transaction took less time than expected. Prototype experiments have shown that the new proposal is much more efficient, in terms of computational cost, than the most complete previous existing system, while providing the same functionalities and higher security.

传统的现票和现票售票机目前共存，但可能会在不久的将来被电话支付应用所取代。这样的应用程序方便了在规定区域停车的付款。提供这项服务的公司收集并管理有关驾驶员执行的所有停车交易的信息。该信息非常敏感，可用于生成有关驾驶员停车历史的报告，对他们的隐私构成威胁。本文提出了一种通过电话付费的停车系统，在该系统中，服务提供商无法跟踪驾驶员的停车交易。新建议要求仅在停车交易开始时或指示停车交易花费的时间少于预期的时间连接驾驶员。