2. EUROCONTROL EXPERIMENTAL CENTRE1 INNOVATIVE RESEARCH Advanced Speech Watermarking for Secure Aircraft Identification Konrad Hofbauer PhD student, signal processing. Graz University of Technology, Austria. Surpervisors Gernot Kubin (TU Graz) Horst Hering, Vu Duong (EEC)

3. EUROCONTROL EXPERIMENTAL CENTRE2 INNOVATIVE RESEARCH AIT – Aircraft identification tag TX RX Aircraft system Ground system PTT* switch * PTT (Push To Talk) Data (e.g. SSR code, Mode S, tail nr.) Watermark Encoder Tag Watermark Decoder Data and Security Information VHF channel

4. EUROCONTROL EXPERIMENTAL CENTRE3 / INNOVATIVE RESEARCH Track 4 Track1 Track2 Track3

5. EUROCONTROL EXPERIMENTAL CENTRE4 INNOVATIVE RESEARCH Target objectives Adaptive channel equalisation for highly time-varying systems Cryptography for systems with low data rate Air-ground communication channel simulation and measurement Speech impairment due to noise signals above the auditory masking thresholds Watermarking and data hiding algorithms Increasing intelligibility of speech signal. Detecting unauthorised radio transmissions. Keeping error rate (system reports incorrect identification) smaller 10 -4. Minimising the audibility and annoyance of introduced perceptual impairment. Including aircraft position (by increasing payload data rate to up to 100 bit/s). Perceived quality Security Reliability Inaudibility Capacity

6. EUROCONTROL EXPERIMENTAL CENTRE5 INNOVATIVE RESEARCH konrad.hofbauer@eurocontrol.int Thank you for your attention!