Text Steganography on Sundanese Script using Improved Line Shift Coding

Steganography allows confidential information to be inserted through multimedia (text, video, image and audio). Text steganography changes the text format or the character of a particular text without changing the meaning of the text. Sundanese script, which already registered in the official version of the Unicode font, can be used as an alternative media to be a cover text in text steganography technique. Text steganography technique has the vulnerability to experience information loss due to attack or malfunction such as printing process with the printer and reprinting by copy machine. The line shift coding approach is used to produce good robustness level stego text and reduce the damage caused by the printing and scanning process. Line shift coding inserts binary bits of secret messages by vertically shifting the row position. The insertion of confidential information in Sundanese script steganography text replaces the Unicode character block on the shifted row. Contribution of this research is improving the secret message capacity. In ordinary line shift coding, odd row is the pivot and the secret bit is inserted on the line between those two pivots. In the improved line shift coding, we use the first and the fifth row as the pivot line to increase the message capacity. The experimental results shows the improved line shift coding has higher capacity and the stego text is able to withstand printing process and copying process up to two reprints to retain the confidential messages.