Using Blowfish encryption to enhance security feature of an image
Shreyank N Gowda · 2016
The use of images to hide information is a feature which leaves little doubt in a viewer's mind. Using any medium to hide information refers to a method called steganography. When we use an image as a medium then that method is called image steganography. The most famous method to now is the Least Significant Bit Algorithm (LSB). In that method, the least significant bit of each pixel is taken and information is hidden in that. This however is easily breakable. Hence an alternative and more secure solution is provided. First the data is encrypted using the Blowfish algorithm. Next an innovative method is presented. This encrypted block is broken down to `n' smaller blocks and `n' images are chosen at random and each image is made to hide a block of the encrypted data. To maintain the correct sequence of blocks a hash table is maintained. This is then encrypted using LSB to a new image called the hashing image. This hashing image is sent along with the `n' other images. To extract the data out, first the hash image is obtained and using this the encrypted block is reassembled and then original data is obtained by decryption.