Ledya Novamizanti

Implementation of steganography using LSB with encrypted and compressed text using TEA-LZW on Android

The development of data communications enabling the exchange of information via mobile devices more easily. Security in the exchange of information on mobile devices is very important. One of the weaknesses in steganography is the capacity of data that can be inserted. With compression, the size of the data will be reduced. In this paper, designed a system application on the Android platform with the implementation of LSB steganography and cryptography using TEA to the security of a text message. The size of this text message may be reduced by performing lossless compression technique using LZW method. The advantages of this method is can provide double security and more messages to be inserted, so it is expected be a good way to exchange information data. The system is able to perform the compression process with an average ratio of 67.42 %. Modified TEA algorithm resulting average value of avalanche effect 53.8%. Average result PSNR of stego image 70.44 dB. As well as average MOS values is 4.8.

Designing secured data using a combination of LZW compression, RSA encryption, and DCT steganography

Information security in mobile phones has become a challenge when large amounts of data exchanged on the Internet. Secure information transfer can be achieved by cryptography and steganography. Cryptography is a tool that provides encryption techniques for secure communication. Steganography is the technique of hiding information by way of the message of the picture, so that in addition to the person addressed, another person will not be aware of the existence of the message. In this study the issues to be discussed is the technique of message encryption with RSA (Rivest Shamir Adleman) method. Messages are encrypted after compressed by LZW (Lempel Ziv Welch) method, so it will reduce the size of the message that will be inserted and increase the capacity of messages that can be inserted. Messages that have been compressed and encrypted, is then hidden by DCT (Discrete Cosine Transform) techniques. With the incorporation of encryption techniques, steganography, and compression, the acquired information is more secure and its capacity is larger. For a 512×512 colored image there are 1536 characters enable for hiding. With LZW the amount of characters hiding will be about twice larger in this research.