132 Informatica Economică vol. 14, no. 4/2010 Aspects of a Watermark Solution Dominic BUCERZAN 1 , Crina RATIU 2 , Ioan DASCAL 2 1 Aurel Vlaicu University from Arad, Romania 2 Vasile Goldis University from Arad, Romania dominic@bbcomputer.ro, ratiu_anina@yahoo.com, nelu_dascal1@yahoo.com Although watermarking is a relatively new technology, there are many ways of applying it on an electronic data set with the purpose of ensuring copyright integrity and authenticity of the electronic data. But, bearing in mind the evolution of information technology and of communication, a watermark may be the target of several attacks which aim at its robustness, its form and even at its removal. In order to reduce these threats, this paper proposes a solution - digital watermarking completed by a hash function which has an important role in the authenticity of the content of a message and in the security of the transmission of this message through computer networks which are the main support of collaborative systems. Keywords: Digital Watermarking, Hash Functions, Digital Information Security, Collaborative Systems Introduction Digital Watermarking is associated with the old technique of hiding information, namely steganography. This kind of marking hides a secret of a personal message, in order to protect the right of property or to demonstrate authenticity. It is also possible to verify the originality of the message, check its content and data integrity in order to detect fraud. The marking of digital images, audio, video or electronic data in general, has as main target the establishing of the right of property and the checking of the original content. Taking into consideration its features developed so far, we consider digital Watermarking a solution for ensuring the authenticity of shared information into collaborative activities like: collaborative e- Business, Web-Business and collaborative Education. We consider that the positive impact on securing this collaborative transaction is improved by our proposal to use an additional hash function. The new digital technology for creating, processing and stocking multimedia products has been considered by its designers, producers, editors and clients to be extremely useful. Simultaneously digital communication through computer networks has increased rapidly. Digital products may be easily copied, processed for various goals or publicly exposed. Digital Watermarking consists of a signal inserted into an image, an audio signal or video signal inserted into any digital document. [1] Watermark may be a series of numbers, the name of a company or someone’s signature. The main feature of a watermark is that it cannot be seen or heard. So, if we see and listen to a multimedia object which contains a watermark, we cannot detect the watermark signal. However, the watermark may be detected and extracted with a certain algorithm. The need to protect digital information against fraud and illegal manipulation has occurred in the same time with the communication through Internet. Electronic publishing and electronic commerce of digital information increase the danger of fraud and of intellectual theft [2]. As far as analogical signals are concerned, the problem solves itself, because by copying these kinds of data we get a lower quality than the original one audio and video file). On the other hand, digital information can be perfectly copied and it is difficult, if not impossible, to make the distinction between the original and copied version. Besides, there is not a mechanism that can help us 1