VoIP is a solid technology available since some years that allows people to communicate via voice using the IP protocol instead of telephone lines.

Unfortunately this technology has been relegated in a niche market due to several factors such as proprietary standards, high price tag, limited integration with existing telephony environments. However in the last couple of years the situation changed dramatically since some open source tools such as asterisk [asterisk] as well as low-cost VoIP telephone adapters and services become available. In fact, today it is quite common for internet providers to provide their customers VoIP calls at very low cost, if any, in addition to standard xDSL connectivity. More…

We present the new watermarking scheme which guarantees the even time adjustment for embedding the watermark in real time and has all the theoretical strengths of work. Unlike the watermarking scheme proposed in previous work [32], our new watermarking scheme is probabilistic in the sense that the watermark embedding success rate is not guaranteed 100%.

In other words, the new watermarking scheme trades o® the guaranteed 100% watermark embedding success rate with the guaranteed even time adjustment for embedding the watermark. By exploiting the inherent inter-packet timing characteristics of the VoIP °ows, our new watermarking scheme achieves virtually 100% watermark embedding success rate with guaranteed even time adjustment for embedding the watermark.

Source: Chief Information Officers of the States