Resumo

ESPEJEL, Angelina; NAKANO, Mariko  e  PEREZ, Héctor. Comparison between various visual extended cryptography algorithms. Inf. tecnol. [online]. 2012, vol.23, n.4, pp. 105-124. ISSN 0718-0764.  doi: 10.4067/S0718-07642012000400013.

A description and comparison of three visual extended cryptography algorithms is presented. Currently these methods are often used as a basis for developing more complex schemes. Results related to overlapping shades, pixel expansion, quality of images and shades, and the number of coded images are obtained. In conventional visual cryptography a secret image is encrypted into a set of images that look like random-noise and are distributed to each participant of the scheme. To obtain the secret image the images received must be super-imposed. .In the extended visual cryptography the shades are visually recognizable images. It is concluded that the three methods present particular advantages depending on the application.

Palavras-chave : visual cryptography; extended visual cryptography; secret sharing scheme.