Application Scenario: Car Sharing

Within the last decade, the car sharing market has grown exponentially and the rapid development of car sharing solutions is drastically changing the transportation landscape, especially in metropolitan areas. Reasons for this are diverse and include, i.a., a general growth of world’s urban population and a changing mobility concept in favor of car sharing’s on-demand car access. By offering anytime access to a network of vehicles for short-term use, car sharing solutions preserve the users' mobility while decreasing associated costs that come with car ownership. Moreover, they improve the traffic and parking situation in urban areas and address environmental issues by reducing CO₂ emission due to decreased number of cars per user.

Motivated by the rapid development in the car sharing sector, Fraunhofer SIT developed a car sharing solution which is based on the Key2Share smartphone-based access control system and therefore inherits Key2Share's security features.

Advantages

Despite the fact that there is a variety of car sharing solutions already deployed in the field, these suffer from various shortcomings that typically include a mandatory online connection of the cars in order to open them, a cumbersome user registration process for smartcard-based solutions that involve either a physical meeting with the car sharing provider or long waiting times to retrieve the card via mail and, for app-based solutions, a platform security concept that relies solely on OS-level security mechanisms.

These shortcomings are addressed by Fraunhofer's car sharing solution. It supports (i) offline car access by utilizing short-range wireless communication interfaces to communicate with the respective cars via smartphone. This allows to utilize the service also in areas without any network connections like underground carparks. Furthermore, the solution (ii) enables a fast user registration that avoids long waiting times by handling the registration process solely online and (iii) protects security-critical data in an isolated environment where current solutions typically rely solely on OS-level security mechanisms to secure the platform. This isolated environment can either be instantiated on the smartphone itself to achieve software-based isolation or can be hosted on any external Java- or Android-based platform to achieve true hardware-based isolation which is resistant to all software-based attacks trying to gain unauthorized access to security-sensitive data.