System Definition

The problem definition is to suggest a system capable of carry out lossless data compression on binary data using encryption and decryption. It also works as a solution to the data protection needs of the user, holding important role in environments where privacy of data is critical and therefore contributing to information security. The encoding and compressing schemes need to be computationally and functionally efficient and must look up to provide an optimal solution to the above-mentioned problems.

The system is capable of taking input in the form of text files whose binary representation is processed and thereby encrypted in a color image. One of the suitable compression method for data compression which is known as Huffman encoding is used on the encrypted data to ensure a proper adjustment between the tasks performed and space complexity issues involved. The design should attain the best promising compression ratio, with the limited resources of a present-day computers. As a result, there are firm constraints on the memory usage and the compression speed of the design. The system presently aims to work with text file in standard ASCII based format.

The system performs on two aspects: On the Sender side this technique compresses the file using Huffman encoding and then encodes the binary file data into a color code encrypted JPEG image file. While On the Receiver side, it does the reverse i.e. decrypts the image and then decompresses it, bringing back the binary text file.Fig. 1 shows the block diagram of the Encryption Process at the Sender side. Given a stored text file that is to be encrypted and compressed, the system first converts the file into its binary representation thereafter it forwards the binary file to the Huffman Compressor which performs compression on the binary data by transforming into a vector. The vector is next given as input to Color Coded Encoder, which converts numeric vector data into colored JPEG image.

The encrypted colored image has a series of colored blocks. The process of color assignment is predefined and is done by grouping three bits of the binary data stream together at a time, hence gives a possibility of 8 colors in allFig. 2 shows the block diagram of the Decryption Process at the Receiver side. At the receiving end, the system takes the encrypted image as input. The system verifies the color of the dissimilar blocks iteratively and then takes a mean of values for getting a practical viewpoint of the color of the particular block. Using this process of decryption, it recreates the vector data. The vectored data is next forwarded to the Huffman Decompressor, which converts the data back to the original binary representation as it was given in the input. The binary file is translated back to the original ASCII text file, hence restoring the text file and completing the lossless decompression at the receiver side.