Secret encryption using (2, 2) visual cryptography scheme with DCT compression

摘要

Cryptography is the study of encoding and decoding the information in secure form, from unintended recipients. Visual Cryptography is the method of cryptography that encrypts any visual information (such as pictures, text, handwritten notes etc.) in such a way that decryption is done by using human visual system without the help of computer. Due to rapid progression of data exchange through internet, information security has become more important in data transmission and storage. Because of highly usage of images in industrial process, it is important to protect the confidential image data from unauthorized access. Now a days images are transferred over internet and for larger size image it affects transmission speed. Hence different image compression and decompression techniques are used mainly to have high data rates. The paper proposes a solution to image security as a fusion of visual cryptography and image compression technique. Discrete cosine transform with visual cryptography enhance the security level of image over internet.