A Model for the Secured Data Transfer of Healthcare Data by Image Steganography and Cryptography Techniques

A Model for the Secured Data Transfer of Healthcare Data by Image Steganography and Cryptography Techniques

Health care domain and related issues have evoked a lot of attention from researchers in the recent past. Ensuring the Security and Privacy of data of patients having classified disease is of utmost importance to the health care sector. From time immemorial cryptography and steganography techniques were used to provide data security. In health care domain, classified disease is the area of investigation as the patients having classified disease always prefer more security and privacy. The objective of this research work is to extract the benefits of cryptography and steganography techniques and to apply the combination of these security mechanisms to develop an algorithm that gives more security and privacy than existing techniques. The proposed algorithm builds on Rivest, Shamir and Adleman (RSA)algorithm which is considered to be one of the classical algorithms in cryptography. RSA is widely used in the encryption-decryption process for data transfer in internet which ensures the security of data in transit. The data encrypted using RSA is provided with one more layer of protection by calculating the message digest of the same. The message digest of encrypted data is calculated using message digest (MD5) algorithm. The steganographic approach of spread spectrum gives better security as it is always robust against statistical attacks and provides added security to the cryptographic protected data. Finally the Discrete wavelet transform (DWT) method is used for transformation. Combination of cryptographic technique and steganographic techniques offers higher level security to the data dealt in health care domain. Image type is a major factor contributing to the performance of the proposed algorithm. In recent years the open sources such as internet shows rapid usage of images especially Joint Photographic Experts Group (JPEG) image format as it occupies comparatively less space and provides better image quality even after applying image transformation. So medical image format type selected for the discussed research work is of JPEG format. Medical images of patients like X-ray of lung, bilateral section of face etc. are taken as cover image for the developed algorithm. Patients personal data is very confidential which is in the textual format is encrypted using RSA algorithm, then message digest is incorporated to keep the encrypted data homogeneous and then it is embedded in the cover image using DWT technique. The performance of the algorithm developed is measured on the basis of peak signal to noise which is a statistical method. The peak signal to noise ratio measurement is used as a visual quality measurement to simulate human perception as the difference between original image and embedded image seems to be identical as per developed algorithm. PSNR ratio is measured for various medical images selected. Noise ratio is also measured for Lena image as it is considered as a standard cover image in the steganography. Noise ratio of the selected medical images are measured and compared against cropped medical images. The results of the above research exercise presented in the thesis, infers that the proposed algorithm Raster Data protection algorithm provides enhanced security to the embedded medical images dealt within the health care sector, with minimal side effect on the quality of the image. KEYWORDS: Cryptography, Steganography, Health care, Security, JPEG, PSNR.

C.S Sreeja.

Computer Science