# A Novel Fragmented Approach for Securing Medical Health Records in Multimodal Medical Images
## 1 Introduction  
Privacy and the right to keep private information confidential are key issues facing computer security experts. There are always attempts from unauthorized individuals to access information and data for various reasons, whether for the mere reason of prying into people's private affairs or for hacking attempts to cause damage. Regardless of the motives, computer security experts are constantly developing innovative techniques to encrypt and hide data so that even if it falls into the wrong hands, they will be able to neither decrypt nor see where the data are hidden. Steganography refers to hiding secret information or messages in multimedia objects using complex mathematical techniques in a way that does not show that information is being hidden. It is usually referred to as the technology and science of choice involving communicating secret data in different types of appropriate multimedia carriers such as audio, text, video, or image [1]. Though thefield of cryptography has matured considerably, sometimes even the presence of a secret message is not desirable to prevent interception and possible decryption. While many do not differentiate between cryptography and steganography because both are used for sending secret messages, the distinction between these is very clear. Steganography refers to the process of concealing a secret message in a cover image so that it has no meaning except to the intended receiver, while cryptography converts the secret text message to an unreadable format [2]. The most common techniques for hiding messages are steganography and watermarking. However, invisible messages can only be sent through the steganography methods. In steganography, the messages are hidden in other forms of media, which are called carriers or covers. The media used as cover could be audio, text, or an image file. In this paper, carrier media will be referred to as a cover image since image files will be used as the carrier. The hidden secret will be called \"payload,\" and a payload embedded in a cover image will be called a stego image throughout this paper. To judge a good stego image, the statistical properties must stay intact so that the secret message is ensured to stay hidden. Only the receiving end should be able to detect the hidden message. Among the many existing steganography techniques, least significant bit (LSB) has been the most widely used and researched method. Medical Health Records are considered highly private data and must be protected from unauthorized user access. Patient confidentiality entails that only authorized physicians and medical personnel have access to such records. Many hospitals and medical institutions use medical health record systems. However, even these systems can be susceptible to hacking and other vulnerabilities that could result in patient data becoming available to unauthorized users. Thus, as an additional precaution, we also propose a method to hide the text-based portions of medical health records within medical images. Therefore, even if an unauthorized user accesses the file, they will only be able to see a medical image with no identifying marks or text-based health records to indicate the personal information of the patient. Overall, the objective of the proposed technique is to generate an embedded image that is the original one since a minor part of the pixel values will be changed. Consequently, neither decryption algorithms nor bare eyes can identify or detect any change in that stego image color and its cover image. In this paper, we propose a novel method in which the original text document is first encrypted, and then the document is fragmented into several documents, each containing a portion of the original document that is not comprehendible on its own, even if detected and decrypted. A key generator is proposed to randomly select medical images from the patient's file according to the number of files generated from the fragmentation. These portions are then embedded into the images using the proposed novel steganography method.