Title |
Chaotinė vizualinė kriptografija / |
Translation of Title |
Chaotic visual cryptography. |
Authors |
Palivonaitė, Rita |
Full Text |
|
Pages |
152 |
Keywords [eng] |
visual cryptography ; moire fringes ; time series segmentation ; time series forecasting ; evolutionary algorithms |
Abstract [eng] |
Visual cryptography is a cryptographic technique which allows visual information to be encrypted in such a way that the decryption can be performed by the human visual system, without any cryptographic computation. Dynamic visual cryptography is an alternative image hiding method that is based not on the static superposition of shares, but on time-averaging geometric moiré. This method generates only one picture, and the secret image can be interpreted by human visual system only when the original encoded image is harmonically oscillated in a predefined direction at strictly defined amplitude of oscillation. Experimental implementations of dynamic visual cryptography require generation of harmonic oscillations. Unfortunately, a nonlinear system excited by harmonic oscillations could result into a chaotic response. Therefore, the concept of chaotic dynamic visual cryptography is an important problem both from the theoretical and practical points of view. The feasibility of chaotic dynamic visual cryptography is one of the main topics in this dissertation – theoretical relationships and computational experiments are derived and discussed in details. Dynamic visual cryptography scheme based on the deformations of the cover image and improved dynamic visual cryptography schemes with enhanced security are provided as well. |
Dissertation Institution |
Kauno technologijos universitetas. |
Type |
Doctoral thesis |
Language |
Lithuanian |
Publication date |
2015 |