Digital watermarking in medical images

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 05/12/2005.This thesis addresses authenticity and integrity of medical images using watermarking. Hospital Information Systems (HIS), Radiology Information Systems (RIS) and Picture Archiving and Communication Systems (P ACS) now form the information infrastructure for today's healthcare as these provide new ways to store, access and distribute medical data that also involve some security risk. Watermarking can be seen as an additional tool for security measures. As the medical tradition is very strict with the quality of biomedical images, the watermarking method must be reversible or if not, region of Interest (ROI) needs to be defined and left intact. Watermarking should also serve as an integrity control and should be able to authenticate the medical image. Three watermarking techniques were proposed. First, Strict Authentication Watermarking (SAW) embeds the digital signature of the image in the ROI and the image can be reverted back to its original value bit by bit if required. Second, Strict Authentication Watermarking with JPEG Compression (SAW-JPEG) uses the same principal as SAW, but is able to survive some degree of JPEG compression. Third, Authentication Watermarking with Tamper Detection and Recovery (AW-TDR) is able to localise tampering, whilst simultaneously reconstructing the original image

Information hiding through variance of the parametric orientation underlying a B-rep face

Watermarking technologies have been proposed for many different,types of digital media. However, to this date, no viable watermarking techniques have yet emerged for the high value B-rep (i.e. Boundary Representation) models used in 3D mechanical CAD systems. In this paper, the authors propose a new approach (PO-Watermarking) that subtly changes a model's geometric representation to incorporate a 'transparent' signature. This scheme enables software applications to create fragile, or robust watermarks without changing the size of the file, or shape of the CAD model. Also discussed is the amount of information the proposed method could transparently embed into a B-rep model. The results presented demonstrate the embedding and retrieval of text strings and investigate the robustness of the approach after a variety of transformation and modifications have been carried out on the data

Modified algorithm for image watermarking using 2D-DCT and elgamal cryptosystem / Nur Azien Yazid, Kamilah Abdullah and Suhaila Abd Halim

Image watermarking embeds identifying information in an image in such a manner that it cannot easily be removed. For the past several years, image digital watermarking has become a necessary element used for hid ing secret image and enabling secured communication such as privacy, confidentiality, authentication and data integrity. Although numerous watermarking schemes are present in grayscale images, the present work focuses on the RGB color image. This study proposed a new hybrid method that would satisfy the essential needs of modern image watermarking. The color image watermarking is based on the 2D Discrete Cosine Transform and Egamal cryptosystem.The 2D Discrete Cosine Transform depends on the matrix products, while the ElGamal cryptosystem depends on the discrete logarithm problem. The cryptosystem is combined with existing Arnold transform in watermarking algorithm to enhance the security of secret image. Value of Peak Signal to Noise Ratio was taken as performance evaluation parameters. On the whole, the performance evaluation shows that combining the two algorithms improved the performance of image watermarking

Digital watermarking : applicability for developing trust in medical imaging workflows state of the art review

Medical images can be intentionally or unintentionally manipulated both within the secure medical system environment and outside, as images are viewed, extracted and transmitted. Many organisations have invested heavily in Picture Archiving and Communication Systems (PACS), which are intended to facilitate data security. However, it is common for images, and records, to be extracted from these for a wide range of accepted practices, such as external second opinion, transmission to another care provider, patient data request, etc. Therefore, confirming trust within medical imaging workflows has become essential. Digital watermarking has been recognised as a promising approach for ensuring the authenticity and integrity of medical images. Authenticity refers to the ability to identify the information origin and prove that the data relates to the right patient. Integrity means the capacity to ensure that the information has not been altered without authorisation. This paper presents a survey of medical images watermarking and offers an evident scene for concerned researchers by analysing the robustness and limitations of various existing approaches. This includes studying the security levels of medical images within PACS system, clarifying the requirements of medical images watermarking and defining the purposes of watermarking approaches when applied to medical images

A novel image authenticationand rightful ownership detection framework based on DWT watermarking in cloud environment

Cloud computing has been highlighted by many organizations because of its benefits to use it anywhere. Efficiency, Easy access information, quick deployment, and a huge reduce of cost of using it, are some of the cloud advantages. While cost reduction is one of the great benefits of cloud, privacy protection of the users‘ data is also a significant issue of the cloud that cloud providers have to consider about. This is a vital component of the cloud‘s critical infrastructure. Cloud users use this environment to enable numerous online transactions crossways a widespread range of sectors and to exchange information. Especially, misuse of the users‘ data and private information are some of the important problems of using cloud environment. Cloud untrustworthy environment is a good area for hackers to steal user‘s stored data by Phishing and Pharming techniques. Therefore, cloud vendors should utilize easy- to-use, secure, and efficient environment. Besides they should prepare a way to access cloud services that promote data privacy and ownership protection. The more data privacy and ownership protection in cloud environment, the more users will attract to use this environment to put their important private data. In this study, a rightful ownership detection framework has been proposed to mitigate the ownership protection in cloud environment. Best methods for data privacy protection such as image authentication methods, watermarking methods and cryptographic methods, for mitigating the ownership protection problem to use in cloud environment, have been explored. Finally, efficiency and reliability of the proposed framework have been evaluated and analyzed