Abstract:
In recent years, due to the rapid development of digital communication medical diagnosis
and treatment procedures are emerged and we can think about the establishment of ehealth. To establish such an important electronic health recording system continuous
communication between patients and doctors are inevitable where data security demands
the most priority. During this communication, the most important and large diagnostic
data are images acquired from numerous modalities like X-ray, MRI, CT, PET, SPECT,
ultrasound, etc. Since it is essential to protect the privacy of patients’ medical records,
these images should be encrypted before being digitally transmitted. Conventional
encryption techniques hold some drawbacks like static keys, long computational time,
recognizable patterns even after encryption, a large amount of loss in the decryption
process, mandatory large key size, and so on. To resolve these issues as well as to
maintain a higher security level, this thesis proposes an efficient encryption-decryption
system which is a combination of two renowned methods RSA and steganography with
some constructive modifications. The proposed system generates images of an
unidentifiable pattern after encryption in a short amount of computational time and
lossless decrypted images. Besides, this proposed method produces different keys for
each image dynamically that increase the security system. The claimed performances of
the system were justified using different numerical and graphical measures such as
PSNR, MSE, SSIM, and histograms. The proposed method ensures lossless retrieval of
the shared image while preserving a high degree of robustness and efficiency.
