New robust and secure alphabet pairing Text Steganography Algorithm

Steganography has been practiced since ancient times. Many Linguistic Steganography (popularly known as Text based Steganography) algorithms have been proposed like Word Spacing, Substitution, Adjectives, Text Rotation, Mixed Case Font etc.. Information Hiding effectively means that the method/technique should be Robust, Secure and have good Embedding capacity. Measure of Similarity between cover text i.e. original text or message and Stego text through Jaro Winkler distance gives an indication of whether the Stego text can actually embed the text. The proposed algorithm consists of embedding the secret text in the original message by pairing the secret message alphabet into 4 parts of 2 bits each. The last word of the original message will consist of the position of the secret message alphabets in its ASCII equivalent. Decryption steps consist of decoding the position of the secret message in the original message and extraction by the pairing method so that the secret message can be found. Jaro Winkler Distance is 1 as there is no extra substitution in the original message except the last word showing the position which becomes part of the message and cannot be detected making it secure. Keywords—Linguistic Steganography, Information Hiding, Decryption,Secure, Size, Robust, Embedding capacity, Pairing of bits, Stego text, ASCII, Original message, Secret message , Jaro Winkler Distance, Substitution.