Shared secret-based steganography for protecting medical data

Medical data (i.e., medical image and medical record) is private which should be protected before being transferred or stored. There have been some methods proposed by implementing various algorithms, such as steganography. It is sometimes combined with the shared secret method, so that, the reconstruction of the original data must be done by some users. It is believed that this method increases the security of the data. However, there is still a need to make the stego data (i.e, stego image) has an as good as possible quality. This means that the stego image has high similarity to the cover (carrier) image. In this paper, we propose methods to protect the medical data by using the shared secret mechanism and steganography for 2 and 1 bit LSB. The experimental results show that they produce relatively good quality (similarity) in terms of PSNR.