Watermarking has been applied to protect relational databases from illegal copying and manipulation by attackers. Many watermarking schemes for relational database have been proposed, and these schemes both rely on the actual primary key. Therefore, the watermark cannot be embedded into relational database, if there is not existence of actual primary key. In this paper, we present a new reversible watermarking scheme for textual relational database without depending on the actual primary key. The proposed scheme constructs a virtual primary key from the content of some selected textual attributes. Based on the generated virtual primary key, the watermark is embedded into the textual relational database. Experimental results showed that the proposed scheme achieves strong robustness under a variety of possible attacks, e.g., sorting, deletion, modification, and addition attacks. In addition, in comparisons with three previous schemes, the proposed scheme was more secure and robust, as evidenced by our experimental results and robustness analysis.
In the realm of electronic health (eHealth) services powered by the Internet of Things (IoT), vast quantities of medical images and visualized electronic health records collected by IoT devices must be transmitted daily. Given the sensitive nature of medical information, ensuring the security of transmitted health data is paramount. To address this critical concern, this paper introduces a novel data hiding algorithm tailored for Absolute Moment Block Truncation Coding (AMBTC) in medical images, named HPDH-MI (High Payload Data Hiding for Medical Images). The proposed method embeds secret data into the AMBTC compression code inconspicuously to avoid detection by malicious users. It achieves this by first classifying AMBTC compressed blocks into four categories—flat, smooth, complex I, and complex II—using three predetermined thresholds. A 1-bit indicator, based on the proposed grouping strategy, facilitates efficient and effective block classification. A data embedding strategy is applied to each block type, focusing on block texture and taking into account the symmetric features of the pixels within the block. This approach achieves a balance between data hiding capacity, image quality, and embedding efficiency. Experimental evaluations highlight the superior performance of HPDH-MI. When tested on medical images from the Osirix database, the method achieves an average image quality of 31.22 dB, a payload capacity of 225,911 bits, and an embedding efficiency of 41.78%. These results demonstrate that the HPDH-MI method not only significantly increases the payload for concealing secret data in AMBTC compressed medical images but also maintains high image quality and embedding efficiency. This makes it a promising solution for secure data transmission in telemedicine, addressing the challenges of limited bandwidth while enhancing steganographic capabilities in eHealth applications.
To support users' purchase of digital content over a mobile network, a mobile trading scheme for digital content based on the digital rights concept is proposed in this paper. Based on our proposed mobile trading scheme, not only can content providers transmit authorized digital content to service providers according to predefined contracts, but consumers can also purchase digital content through their telecommunication companies via mobile personal devices, and the purchasing costs can be charged by the telecommunication companies. The proposed scheme supports mobile users' purchase of digital content in both the home domain and any visited domain. Moreover, the proposed scheme provides authentication, non-repudiation and confidentiality properties and makes sure the obligations and rights of participants are not violated.
Background: In Taiwan, the number of cases of sequential bilateral pediatric cochlear implantation (CI) is increasing but data regarding its effectiveness and impact of the reimbursement policy are lacking. We examined the speech perception and quality of life (QOL) of bilateral prelingually deaf children who underwent sequential CI, considering the effects of age at the time of second implantation and interimplant interval. Methods: We enrolled 124 Mandarin-speaking participants who underwent initial cochlear implant (CI1) in 2001-2019 and a second CI (CI2) in 2015-2020. Patients were followed up for ≥2 years and were categorized into groups based on age at the time of CI2 implantation (<3.5, 3.6-7, 7.1-10, 10.1-13, and 13.1-18 years) and interimplant interval (0.5-3, 3.1-5, 5.1-7, 7.1-10, and >10 years). We evaluated speech perception, device usage rates, and QOL using subjective questionnaires (Speech, Spatial, and Qualities of Hearing and Comprehension Cochlear Implant Questionnaire). Results: Speech perception scores of CI2 were negatively correlated with ages at the time of CI1 and CI2 implantation and interimplant interval. Older age and a longer interimplant interval were associated with higher nonuse rates for CI2 and worse auditory performance and QOL. Among individuals aged >13 years with interimplant intervals >10 years, up to 44% did not use their second ear. Patients aged 7.1 to 10 years had better speech perception and higher questionnaire scores than those aged 10.1 to 13 and 13.1 to 18 years. Furthermore, patients aged 10.1 to 13 years had a lower rate of continuous CI2 usage compared to those aged 7.1 to 10 years. Conclusion: Timely implantation of CI2 is essential to achieve optimal outcomes, particularly among sequentially implanted patients with long-term deafness in the second ear and no improvement with hearing aids following CI1 implantation. For CI2 implantation, an upper limit of age of 10 years and interimplant interval of 7 years are essential to prevent suboptimal outcomes. These data can provide useful information to implant recipients, their families, and medical and audiological professionals, enabling a comprehensive understanding of the benefits and potential impacts of the timing of CI2 implantation.
In the past, most image hiding techniques have been applied only to gray scale images. Now, many valuable images are color images. Thus, it has become important to be able to apply image-hiding techniques to hide color images. In this paper, our proposed scheme can not only be applied to "a color host image hiding a color secret image", but also to "a color host image hiding a gray scale secret image". Our scheme utilizes the rightmost 3, 2 and 3 bits of the R, G, B channels of every pixel in the host image to hide related information from the secret image. Meanwhile, we utilize the leftmost 5, 6, 5 bits of the R, G, B channels of every pixel in the host image and set the remaining bits as zero to generate a palette. We then use the palette to conduct color quantization on the secret image to convert its 24-bit pixels into pixels with 8-bit palette index values. DES encryption is then conducted on the index values before the secret image is embedded into the rightmost 3, 2, 3 bits of the R, G, B channels of every pixel in the host image. The experimental results show that even under the worst case scenario our scheme guarantees an average host image PSNR value of 39.184 and an average PSNR value of 27.3415 for the retrieved secret image. In addition to the guarantee of the quality of host images and retrieved secret images, our scheme further strengthens the protection of the secret image by conducting color quantization and DES encryption on the secret image in advance. Therefore, our scheme not only expands the application area of image hiding, but is also practical and secure.
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