**4.2 Sensitivity to initial condition**

As mentioned before, the chaos system has a sensitivity to the slightest change on initial conditions. This characteristic provides the security aspect of watermarking. For example, the receiver used *μ* = 0.4900 (before was 0.48999), initial conditions *x*0 = 0.5006840 (before was 0.5006841), and *y*0 = 0.538167585 (before was 0.5381675865) to extract the watermark. **Figure 8** shows the extracted watermarks from two frames. The extracted watermarks are wrong! Compared to the original watermark, this extracted watermarks look like the random images. This happens because CCBG produces random bits that are very different from previous bits.

### **4.3 Tamper detection test**

In most cases, a digital video is often edited or manipulated using the video editor. If a video has been manipulated, the video is no longer original. Main goal of fragile watermarking is to determine if the video has been manipulated or not. If the video has been manipulated, the algorithm should able to locate where the alteration made on the video frames. In these experiments, we performed some typical attacks to the watermarked video. The attacks are (1) adding a text to the watermarked video, (2) copy-paste attack, (3) adding some noises, (4) modifying video contrast, and (5) cropping the frames. The following are the attacks.

### **5. Detection test against text addition**

We attack the watermarked video by writing a text "GLASS and WATER" at the left top of the frames (**Figure 9a**). To prove the authentication of the video, we extracted the watermarks from the video frames to get the extracted watermarks. The extracted watermarks contain the text (**Figure 9b**). Therefore, we conclude that the watermarked video has been manipulated. **Figure 9c** shows detection of

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**Figure 10.**

**Figure 9.**

*Application of Chaos-Based Fragile Watermarking to Authenticate Digital Video*

pixels that have been manipulated by adding a text "GLASS and WATER." **Figure 9d**

*(a) Watermarked frame after adding a text; (b) extracted watermark; (c) and (d) detected tampering region.*

In the second attack, we copied an object "coca-cola bottle" and then pasted it into the watermarked video (**Figure 10a**). When we extracted the watermarks from the

*(a) Watermarked frame after copy-paste attack; (b) extracted watermark; (c) and (d) detected tampering region.*

shows the tampered pixels in the correspondence frame.

**6. Detection test against copy-paste attack**

*DOI: http://dx.doi.org/10.5772/intechopen.93151*

*Application of Chaos-Based Fragile Watermarking to Authenticate Digital Video DOI: http://dx.doi.org/10.5772/intechopen.93151*

**Figure 9.**

*Digital Forensic Science*

**4.2 Sensitivity to initial condition**

*The watermarked frames and the extracted (wrong) watermarks.*

previous bits.

**Figure 8.**

**4.3 Tamper detection test**

**5. Detection test against text addition**

As mentioned before, the chaos system has a sensitivity to the slightest change on initial conditions. This characteristic provides the security aspect of watermarking. For example, the receiver used *μ* = 0.4900 (before was 0.48999), initial conditions *x*0 = 0.5006840 (before was 0.5006841), and *y*0 = 0.538167585 (before was 0.5381675865) to extract the watermark. **Figure 8** shows the extracted watermarks from two frames. The extracted watermarks are wrong! Compared to the original watermark, this extracted watermarks look like the random images. This happens because CCBG produces random bits that are very different from

In most cases, a digital video is often edited or manipulated using the video editor. If a video has been manipulated, the video is no longer original. Main goal of fragile watermarking is to determine if the video has been manipulated or not. If the video has been manipulated, the algorithm should able to locate where the alteration made on the video frames. In these experiments, we performed some typical attacks to the watermarked video. The attacks are (1) adding a text to the watermarked video, (2) copy-paste attack, (3) adding some noises, (4) modifying

video contrast, and (5) cropping the frames. The following are the attacks.

We attack the watermarked video by writing a text "GLASS and WATER" at the left top of the frames (**Figure 9a**). To prove the authentication of the video, we extracted the watermarks from the video frames to get the extracted watermarks. The extracted watermarks contain the text (**Figure 9b**). Therefore, we conclude that the watermarked video has been manipulated. **Figure 9c** shows detection of

**46**

*(a) Watermarked frame after adding a text; (b) extracted watermark; (c) and (d) detected tampering region.*

pixels that have been manipulated by adding a text "GLASS and WATER." **Figure 9d** shows the tampered pixels in the correspondence frame.
