Medical Signal Security Enhancement Using Chaotic Map and Watermarking Technique

Introduction

As a fast growing world, everyone uses internet for their communication where they exchange personal information, text, audio, still images, animation video etc. The transmission has been done through channel which arises the word security because it may be possible while image transferred through channel some hacker try to interrupt the channel and get the image or he can even modify the image. Hence, everyone wants security in every field. Thus, many new approaches have been developed to ensure the security proof of originality and authentication. Image encryption is one of the method which has been proposed last few decades which deals with the modification of pixels of digital image (Wang, Ding, Zhang, & Ding, 2008).

In medical field, hospital – treatment – patient – doctors – disease are very common terms which are being used in this field but besides this, there is one more term which is called security in parallel moving in every one’s mind whether he/she is a patient or doctor, because in any treatment hospital updates their database with patient full information like phone number, photo, age, identity proof, mail id, and the disease from which patient suffer, his/her diagnosis etc. Hospital also maintains their database for doctors which contains all information about doctors and also their patient names, their prescriptions to the patients. All these things are updated in their database. All these things are stored on a computer, which may be accessed illegally and someone may misuse the information to make fake identity etc. So, healthcare providers must take proper measures for patient data safety (Agrawal, & Sharma, 2016). PHI i.e. Patient health information referred as from an unofficial access and breaking of privacy and confidentiality. Hence, encryption is the best form of protection of such issues and to preserve the privacy confidentiality. So many different techniques are already introduced for the encryption. The federal government requires the secure handling of electronic media and PHI with standards put forth by the Health Insurance Portability and Accountability Act i. e. called HIPAA of 1996.

On the other hand, when patient visit first time for checkup to the consultant doctor, then that doctor first go through the previous record and documents of that patient before starting the treatment. One possible way is to send medical images along with a specialist report, over a computer network. Computer networks are complex and may be spying by the third party. That time the security problem may arise when patient data is sent over the network. Since security is our first concern and the security issues arise here, the medical imagery cannot be sent. Hence, to avoid such issues, the encryption technique is preferable for the protection of these data. So many different techniques are already introduced for the encryption because it is the best form of protection. Thus, in this chapter we try to provide security to both personnel as well as medical image.

Images are categorized as raster images and vector images. Raster images are defined as bitmap images, which are made up of bits, pixels. Each bit can be visualized as a dot which is defined by number of pixels per unit of measurement and it determines the resolution of the image, which is represented by ppi (pixel per inch) or dpi (dots per inch). Vector images are mathematical arrangements of points, where each point is connected by mathematical formulae. Most of the images are connected by straight lines.

Chittaranjan Pradhan et. al. (2014) explains digital watermarking is the technique which protects the data from being compromised or redistribution. It preserves the integrity and authenticity of the digital data. Digital watermarking technique is divided into two groups on the basis of feature set the watermark is embedded in; i.e. Spatial domain watermarking or Frequency domain (or Transform domain) watermarking. Spatial domain type deals with the image Matrix; whereas transform domain deals with the rate of which pixels value are changing in spatial domain.