The rapid spread of the internet, along with the comprehensive development of digital technologies and easily reproduced digital media, has increased the popularity of media. Nowadays, exchange and transmission of digital images through internet is increasing and thus the protection of image is critical. This has initiated more researchers to develop efficient methods in digital image content protection. Digital watermarking is one of the ways to achieve protection in images. Digital watermarking is a process by which secret data is encrypted into the image without affecting the visual quality of the copyrighted image. This paper presents a block-based image watermarking technology using Discrete Wavelet Transformation (DWT) that does not affect the human visual system. The host images with digital watermark are exposed to cyber attacks when accessible through the open domain in the internet. The experimental results of this study shows that the proposed image watermarking method protects the invisibility of the watermark.