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.