SecureConfig : NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration Thomas Ulz, Thomas Pieber, Christian Steger1 Christian Lesjak, Holger Bock, Rainer Matischek2

Outline • Motivation, State-of-the-art • SecureConfig • Requirements • QR-Code Protocol • NFC Protocol • Smart Sensor Enhancement • Evaluation • Conclusion and Future Work SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Motivation – Industry 4.0 SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Motivation – Smart Homes SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Motivation – Smart Sensor Configuration • Initial manufacturer keys • Initial configuration • Device owner key update • Specific configuration updates • Recurrent configuration updates • Reconfiguration for changing tasks • Reconfiguration for resale • Deletion of confidential data SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

State-of-the-art • Various configuration interfaces • Wired • Wireless (WiFi, Bluetooth, …) • Buttons, Displays, DIP Switches • Using Near Field Communication (NFC) • Wu et al. 2016 • Firmware Updates, not secured • Haase et al. 2016 • Arbitrary Data, some security SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Configuration Interface Requirements • Do not expose configuration interface to network • Use NFC • Suggested by Wu et al. 2016, Haase et al. 2016 • Suitable for smart home and smart factory • Not considered in State-of-the-art • NFC Reader for Smart Home users infeasible • Secured confidential configurations • State-of-the-art not or insufficiently secured SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Configuration Interface Requirements • Configure devices with no power source attached • Prevent tampering with applied configurations • Our contribution: • Approach that meets these requirements • Comprising of protocol and hardware extension SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Hybrid Approach SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

QR-Code Protocol • Two variants, both encrypt payload using Authenticated Encryption (AE) • Inline, no connection to backend required • Up to 2900 bytes of data directly in QR-Code • URL, requires connection to backend • QR-Code contains URL to download configuration SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

NFC Protocol • Based on the NFC Data Exchange Format (NDEF) • Accept Configuration if AE verified and: • Version > current version • Realtime < Validity • Sensor ID matches SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Smart Sensor Enhancement • Requirements • Suitable for new and legacy devices • Tamper resistant • NFC Interface • Networking Interface SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Evaluation • Feasibility: Prototype • Performance: overhead, transfer speed • Security improvements: threat analysis SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Evaluation – Prototype • Built using COTS • Sensor Controller • Infineon XMC4500 • Security Controller (SC) • Infineon SLE78 • Android phone asmobile device SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Evaluation – Performance • Small configuration update of 64 bytes • 200ms, similar to TLS handshake • Overhead • 16 Bytes fixed • + variable overhead • Padding • Length of MAC SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Evaluation – Threat Analysis • Not exhaustive, most relevant threats identified • 2 Assets, 11 threats • Countermeasures for 9 threats • Residual risks for 2 threats SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Evaluation – Threat Analysis • Problems such as weak cryptography, bugsin configuration interface or backdoors • Mitigated by using CC EAL5+ certified SC • Problems with malicious users and adversaries • Mitigated by proposed configuration protocol • Residual risks for DoS attacks by malicious users SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Conclusion and Future Work • QR-Code and NFC Hybrid Configuration Approach • Suitable for smart home and smart factory use cases • Secured by protocol and tamper resistant hardware • Relevant threats mitigated; Acceptable overhead • Future work: SPAKE, attestation mechanism SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

Questions? • Thank you for your attention! • Acknowledgement: SecureConfig: NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration

SecureConfig : NFC and QR-Code based Hybrid Approach for Smart Sensor Configuration