Huge amount of personal information is stored in the mobile devices now. This requires high-qualified security system in order to provide data confidentiality, if the device is lost or stolen. The main part of such system is an authentication module, and there are several methods used to solve this problem. However, traditional schemes, based on usage of text passwords, are not suitable for mobile devices because of their drawbacks. The main drawbacks are bad memorability and inconvenience for the user, if the device does not have a hardware keyboard. In this case Graphical Passwords (GP) can become a good alternative, because of better memorability, ease of input
Ann Ukhanova, DTU Fotonik, PhD student/Researche - team-leader
Vitaly Grinko, SUAI, student
Video communications, as already used in the internet, become the second largest mass service after voice telephony. However video telephony is assumed to be about 10% in 3G networks with voice telephony traffic 5 years after implementation.
With the most modern Video compression techniques, a fast changing video image can be compressed by approx. 10:1. Where the majority of the image is stationary as in video telephony less than 2% of the uncompressed bits need to be sent across the network, relating to a 50:1 to 60:1 compression. This encoding of changes in a video data stream is the essence of MPG ( ISO Motion Picture
Nowadays a lot of digital images are used in different areas of life. For example, almost every mobile device has an embedded photo camera that is mostly used just to make photos. It’s well known that digital images have some special properties ordinary used in compression algorithms. All compression systems use statistical and psychophysitial redundancy of digital images. In many cases (medicine databases with X-ray photos, private photo alboms, etc.) we need additional information about choosen images. It’s possible to solve this task by adding some additional information to initial images and using it by request. This information should be added while creating the image.