German research institute joins the ranks of NFC-based access control

The Fraunhofer Institute for Secure Information Technology (SIT) proudly presents ShareKey, a smartphone solution for NFC-enabled locks. ShareKey turns smartphones into door openers for cars, hotel rooms and offices. Access rights can be flexibly managed with a smartphone app. Particularly, rights can be distributed and revoked remotely, delegated to other users, and can be limited to a certain period of time. Delegated access rights can be represented as QR codes that can be sent via email or SMS, or printed on paper. A special security architecture on the smartphone protects cryptographic keys from malware.

The ShareKey system design addresses the bandwidth constraints of the near-field communication (NFC) interface and the limited computational resources of NFC-enabled lock hardware. The process of checking access rights is very fast: opening a wireless lock with ShareKey takes less than 500 milliseconds. Access rights are encoded in cryptographic tokens, which are created and managed using established security protocols. The ShareKey software considers different approaches for the secure integration into the smartphone platform, starting from a pure software solution which leverages a multilayered software architecture and does not require hardware security anchors, to a solution which leverages security hardware such as smart cards for the protection of cryptographic keys on the device. The solely software-based implementation does not pose additional requirements on the underlying hardware platform. Fraunhofer SIT implemented the solution on common Android smartphones and NFC hardware.