DIGITAL IMAGE AUTHENTICATION USING SELECTIVE LSB WATERMARKING BASED ON INTENSITY AND RANDOM KEYS
Autentikasi citra digital merupakan aspek krusial dalam menjaga integritas data visual dari manipulasi yang tidak sah. Penelitian ini mengusulkan metode watermarking berbasis Least Significant Bit (LSB) selektif yang memanfaatkan intensitas citra dan kunci acak untuk meningkatkan keamanan serta ketahanan autentikasi. Penyisipan watermark dilakukan pada area berintensitas halus dengan bantuan kunci acak, sehingga mampu menjaga kualitas visual citra sekaligus memperkuat aspek keamanan. Hasil pengujian menunjukkan bahwa metode ini mampu mempertahankan kualitas citra dengan nilai PSNR di atas 37 dB dan SSIM mendekati 1, serta terbukti efektif menghadapi berbagai manipulasi citra yaitu kompresi JPEG, penambahan noise, dan serangan geometri. Pengujian lanjutan menegaskan bahwa area intensitas halus merupakan wilayah paling stabil, dengan PSNR mencapai 23,90 dB dan SSIM 0,6450 pada kompresi JPEG 50%, sehingga watermark tetap terdeteksi dengan andal, penelitian ini menawarkan pendekatan yang efisien dan aman untuk autentikasi citra digital.
Authentication of digital images is an essential element in preservation of integrity among visual data when it comes to unauthorized manipulations. This research paper is proposing a selective least significant bit (LSB)-based watermarking scheme which uses image intensity and random keys in order to improve security and robustness of authentication. Watermark embedding is also conducted in the smooth parts of intensities with the help of random keys and hence the aspect of watermarking image maintains the quality of the image itself and enhances the security of the image as well. The experimental findings prove that the algorithm can hold image quality with PSNR metric of over 37 dB and SSIM metric of approximately 1, and that it can be useful in countering a wide range of image manipulations, such as JPEG compression, as well as noise addition and geometric attacks. Subsequent testing allows concluding that the safest regions are ones of smooth intensity, PSNR of 23.90 dB and SSIM of 0.6450 at 50 percent JPEG compression, which is guaranteed to retain the watermark reliably. This paper provides a secure and effective method of authentication of digital images.