Ambiguity attacks on SVD audio watermarking approach using chaotic encrypted images

In this paper, we study the robustness of the proposed watermarking algorithm by Al-Nuaimy et al. (Digit Signal Process 21(6):764–779 2011) for audio signals which is based on singular value decomposition (SVD). It has been concluded that it is fundamentally flawed in its design, in that it falls to two ambiguity attacks where the extracted watermark is not the embedded one but determined by the reference watermark. In the first attack, when a watermarked audio signal is rewatermarked by an attacker’s watermark, this one can be easily extracted to claim ownership of the original audio signal. In the second attack, during the extracting process when an attacker uses the singular vectors of his watermark, he can extract the attacker’s watermark. Therefore, he can claim ownership of the watermarked audio signal. The experimental results prove that the proposed attacks create a false positive detection in watermark extraction. Therefore, Al-Nuaimy et al. algorithm cannot be used for security systems, data hiding and copyright protection.

     

Efficient Use of UAVs for Public Safety in Disaster and Crisis Management

In the case of crisis and disaster situations, Public Safety Organization (PSO) experience situations where most of the telecommunication infrastructure becomes unavailable or not reliable. Thus, an effective disaster assessment of the situation becomes a challenging task for the PSO. UAV is considered as the most suitable solution to address these scenarios where a maximal radio coverage of the target area is crucial. In this work, a square area is considered which mathematical approximation to ensure a maximal coverage based on “covering a square with equal circles” is investigated. The proposed approach outperforms the existing ones as it reduces effectively the total difference delay time to cover the target area. Furthermore, it allows time-saving to achieve more stops at the target area compared to existing schemes leading to better PSO activity performance.