A metamorphic cryptography approach towards securing medical data using chaotic sequences and Ramanujan conjecture

With the increase in telemedicine applications, data authenticity has been one of the major concerns for the received information to confirm the exact diagnosis of the diseases. This paper proposes a fragile watermarking scheme to authenticate medical images to address this. The proposed method utilizes the medical images' two (ISBs) Intermediate Significant Bits for embedding secret data and a fragile watermark. Specifically, the gray-scale fragile watermark of the (EPR) electronic patient report is embedded in the first ISB of the pixel, and secret data is embedded in the second ISB. This dual embedding enhances the authenticity of the images while maintaining low computational complexity compared to other methods. The proposed scheme achieves an average PSNR of 57.68 dB and an SSIM of 0.9990, demonstrating superior fidelity and tamper detection capabilities. These results confirm the method's potential for secure telemedicine applications.

Objective To evaluate the teaching effects of case introduced method based on pic- ture archiving and communication system （ PACS ） system in medical imaging course. Methods Totally 148 students （ 2009 grade ） majored in five-year clinical medicine from Xiangya Medical College were divided into 10 groups; the 10 groups were taken randomly as control group （ n=75 ） and experimental group （ n=73 ）. Control group used traditional teaching methods （ film teaching ） while experimental group used case introduced method based on PACS system. Effects of teaching between were evaluated by questionnaire and test. χ^2 test was used to compare students＇ theoretical test scores, with α level = 0.05. Results Based on results of questionnaires, more students in experimental group than in control group hold that case introduced method based on PACS system can achieve the purpose of teaching, improve interests in learning, and strengthen the mastery of knowledge. Test scores showed that the percentage of students scored 90-100 and 80-89 （ respectively 14%, 75% ） in experimental group was significantly higher than that in control group （respectively 5%, 66% ） （χ^2 =17.932, P=O.O00 ）. Conclusions Application of case introduced method based on PACS system in medical imaging course not only improve students＇ motivation to learn and their clinica~ ability-, but also allow teachers to find and correct short- comings of students timely, therefore, it is worth promoting. Key words: Picture archiving and communication system; Case introduced method; Prac-tice teaching

Because of its own characteristics, chaos has some natural advantages as an important tool in realising the basic principles of cryptography, namely diffusion and confusion, which may generate key sequences with good randomness. However, every coin has two sides. Chaotic sequences still have degeneration problem due to many reasons. Therefore, the reasons of degeneration are first analysed. And one method to improve this problem is also proposed in this paper. A new kind of chaotic key sequence generation system based on n-combination of chaotic mappings is designed furthermore. The simulation results show that, not only can the system generate its own parameters randomly, but also it can generate chaos secret-key sequences, which have the merits of long periodicity, great complexity and strong security, etc.

Medical imaging is a method to produce a visual representation of human body, which is used to do more accurate diagnoses and appropriate treatment to patient. However, medical image can be easily attacked, and it may lead to incorrect diagnoses or treatment. To overcome the attacking issue, this study proposes a security scheme based on dual-layer fragile image watermarking to guarantee the integrity, authenticity and confidentiality of both patient and any important information and the pixel data of medical images. It implements 2 LSBs of image where the 2nd LSB is used to store the patient's and any other important information, and the 1st LSB acts as a tamper detector. The proposed scheme tested on the four deadliest diseases in Indonesia. The result shows that the proposed scheme generates watermarked image without noticeable change compared to original image with PSNR value above 44dB, and the tamper detector correctly detects and localizes any tampering on the watermarked image. Moreover, compared to DICOM Standard watermarking method, the proposed scheme has shown to have a higher level of security on medical images.

Application of digital image processing for the generation of voxels phantoms for Monte Carlo simulation

Medical images stored in a hospital system are generally confidential and integrated and require strict security. However, medical information stored on digital medical imaging systems, as well as picture archiving and communication systems (PACS), are vulnerable to attack when the data are transferred over wireless or wired communication networks. To solve this problem, a watermarking algorithm for medical images is proposed using a bit threshold map based on just noticeable distortion (JND) in the discrete cosine transform (DCT) method. The low-frequency component comprises a considerable amount of the signal energy for most images. As a result, it has a crucial effect on the image quality. Therefore, in this paper, the proposed algorithm embeds watermarks based on the low-frequency components of the image, such as the DC coefficient of the DCT. When watermarks are embedded in a low frequency area, the subjective image quality is often degraded. To compensate for the degradation of the imperceptibility of the watermarking system, which results from embedding watermarks in the low-frequency component, this research considers the human visual system. In addition, the embedding strength of the JND value is used to improve the watermarking imperceptibility. We applied the proposed watermarking algorithm to a variety of medical images using a computer simulation. The algorithm's performance was verified using a variety of attacks for eliminating watermarks. The simulation results show that the proposed algorithm robustly provides protection against a variety of possible attacks.

An encryption frame of medical image with watermark based on hyperchaotic system is proposed in this paper. Medical information, such as the patients’ private information, data needed for diagnosis, and information for authentication or protection of medical files, is embedded into the regions of interest (ROI) in medical images with a high capacity difference-histogram-based reversible data-hiding scheme. After that, the watermarked medical images are encrypted with hyperchaotic systems. In the receiving end, the receiver with encryption key can decrypt the image to get similar images for diagnosis. If the receiver has the key for data hiding at the same time, he/she can extract the embedded private information and reversibly recover the original medical image. Experiments and analyses demonstrate that high embedding capacity and low distortion have been achieved in the process of data hiding, and, at the same time, high security has been acquired in the encryption phase.

Transmission of images on the network is considered insecure which has security-related issues. In this paper, to provide security to digital images, an encryption system that uses four chaotic maps for binary key sequence generation is proposed. The system consists of stages namely, confusion, generation of random binary chaotic key sequence, pseudo-random number generation (RN), and diffusion. Keys for encryption are chosen randomly based on a pseudo random generator from the selected chaotic maps by the linear feedback shift register (LFSR). The algorithm achieves good results in terms of NPCR, UACI, and entropy values. The developed cryptosystem resists differential attacks, is sensitive to minor alterations in the keys, and has a large key space.

The recent introduction of the High Efficiency Video Coding (HEVC) standard provides opportunities to improve medical image compression in picture archiving and communications systems. In this paper, we propose improvements to the HEVC intra coding process for lossless compression of grayscale anatomical medical images, which are characterized by their large amount of edges. Specifically, we propose alternative angular and planar prediction modes that are based on sample-wise differential pulse code modulation (DPCM) with an increased range of directionalities. We also propose an implementation of the DPCM decoding process that maintains the block-wise coding structure of HEVC. Evaluation results on various medical images show that the proposed DPCM modes efficiently predict the large amount of edges in these images achieving bit-rate savings of up to 15%.

Cybersecurity Challenges for PACS and Medical Imaging

This article provides an overview on the literature published on the topic of cybersecurity for PACS (Picture Archiving and Communications Systems) and medical imaging. From a practical perspective, PACS specific security measures must be implemented together with the measures applicable to the IT infrastructure as a whole, in order to prevent incidents such as PACS systems exposed to access from the Internet. Therefore, the article first offers an overview of the physical, technical and organizational mitigation measures that are proposed in literature on cybersecurity in healthcare information technology in general, followed by an overview on publications discussing specific cybersecurity topics that apply to PACS and medical imaging and present the “building blocks” for a secure PACS environment available in the literature. These include image de-identification, transport security, the selective encryption of the DICOM (Digital Imaging and Communications in Medicine) header, encrypted DICOM files, digital signatures and watermarking techniques. The article concludes with a discussion of gaps in the body of published literature and a summary.

The practice of medicine has become extremely technology dependent, and this is especially the case for radiology [1]. Advances in medical imaging and information systems technologies have transformed radiology practice through the creation of new medical imaging techniques (e.g., molecular imaging), data delivery and presentation [e.g., picture archival and communication system (PACS)], and clinical decision support (e.g., CAD). Yet, despite the long-standing history of medical imaging and information technology (IT) innovation, the past few years have been relatively barren. This recent lack of innovation has led to a trend towards commoditization, which is particularly evident in information system technologies, such as PACS and RIS, which just a decade ago, were viewed as groundbreaking and innovative technologies [2]. The recent economic decline has served as a deterrent to R & D expenditures, further perpetuating the cycle of innovation decline [3]. In order to combat this trend in declining innovation, it is necessary to understand the principles of innovation, learn from past successes and failures, and proactively apply this knowledge to ongoing trends in medical practice and economics for guiding future innovation.

To assess the impact of introducing a new Picture Archiving and Communication System (PACS) and Radiology Information System (RIS) on: (i) Medical Imaging work processes; and (ii) turnaround times (TATs) for x-ray and CT scan orders initiated in the Emergency Department (ED). We employed a mixed method study design comprising: (i) semi-structured interviews with Medical Imaging Department staff; and (ii) retrospectively extracted ED data before (March/April 2010) and after (March/April 2011 and 2012) the introduction of a new PACS/RIS. TATs were calculated as: processing TAT (median time from image ordering to examination) and reporting TAT (median time from examination to final report). Reporting TAT for x-rays decreased significantly after introduction of the new PACS/RIS; from a median of 76 hours to 38 hours per order (p<.0001) for patients discharged from the ED, and from 84 hours to 35 hours (p<.0001) for patients admitted to hospital. Medical Imaging staff reported that the changeover to the new PACS/RIS led to gains in efficiency, particularly regarding the accessibility of images and patient-related information. Nevertheless, assimilation of the new PACS/RIS with existing Departmental work processes was considered inadequate and in some instances unsafe. Issues highlighted related to the synchronization of work tasks (e.g., porter arrangements) and the material set up of the work place (e.g., the number and location of computers). The introduction of new health IT can be a "double-edged sword" providing improved efficiency but at the same time introducing potential hazards affecting the effectiveness of the Medical Imaging Department.

Com o advento dos equipamentos digitais de diagnóstico médico, houve uma diminuição do uso de filmes emradiologia. Em contrapartida, o gerenciamento de imagens médicas (IMs) digitalizadas tornou-se uma tarefa crítica. Neste trabalho, apresentamos um protótipo, com base em tecnologias worldwide web (www), que realiza essa função. Ele contempla um servidor de IMs que possibilita a pesquisa e a recuperação dessas imagens armazenadas como arquivos digital imaging and communications in medicine (Dicom), além de receber requisições de serviços de equipamento sem aplicações compatíveis com esse padrão. As IMs podem ser visualizadas e manipuladas dentro de um navegador web (o cliente da aplicação) por meio de uma aplicação Java (applet). Tal abordagem oferece algumas vantagens em relação aos tradicionais sistemas de arquivamento e comunicação de imagens (picture archiving and communication systems [Pacs]), entre as quais a independência de plataformas e facilidade de instalação e de manutenção, a distribuição de dados e a integração com outros sistemas, dentro ou fora da instituição. Basta que se utilize a implementação de políticas de segurança. A simplicidade e a flexibilidade das tecnologias web viabilizam o uso dessa aplicação que provê recursos tanto para o gerenciamento quanto para a manipulação de IMs.

Via the Internet, the information infrastructure of modern health care has already established medical information systems to share electronic health records among patients and health care providers. Data hiding plays an important role to protect medical images. Because modern medical devices have improved, high resolutions of medical images are provided to detect early diseases. The high quality medical images are used to recognize complicated anatomical structures such as soft tissues, muscles, and internal organs to support diagnosis of diseases. For instance, 16-bit depth medical images will provide 65,536 discrete levels to show more details of anatomical structures. In general, the feature of low utilization rate of intensity in 16-bit depth will be utilized to handle overflow/underflow problem. Nowadays, most of data hiding algorithms are still experimenting on 8-bit depth medical images. We proposed a novel reversible data hiding scheme testing on 16-bit depth CT and MRI medical image. And the peak point and zero point of a histogram are applied to embed secret message k bits without salt-and-pepper.