###### Abstract  
XOR-based Visual Cryptography Scheme (XOR-based VCS) is a method of secret image sharing. The principle of XOR-based VCS is to encrypt a secret image into several encrypted images, called shares. No information about the secret can be obtained from any of the shares, and after applying the logical XOR operation to stack these shares, the original secret image can be recovered. In this paper, we present a new XOR-based VCS for grayscale or a color secret image. This scheme encrypts the secret grayscale (or color) image into \(n\) meaningful grayscale (or color) shares, which can import \(n\) difference cover images. After stacking \(n\) shares using the XOR operation, the original secret image can be completely restored. Both the theoretical proof and experimental results show that our method is accurate and efficient. To the best of our knowledge, ours is the only scheme that currently provides this functionality for grayscale and color secret images.  
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Footnote †: journal: Applied sciences  
c 2022  
Accepted: 3 October 2022  
Published: 8 October 2022  
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Footnote †: journal: Applied sciences  
the OR operation as in the VCS; this is known as XOR-based VCS. [PERSON] et al. show that a XOR-based VCS can be implemented using light polarization [10; 11]. Thereafter, many related studies have been proposed [12; 13; 14].  
In addition, all of the shares produced in [1; 2] are meaningless. The researchers found that meaningless sharing schemes found it difficult to manage the shares and the encrypted trace on the shares was easily seen [6]. In order to solve the problems of meaningless shares and develop a XOR-based VCS, [PERSON] and [PERSON], and [PERSON] et al. proposed two XOR-based VCS methods to generate meaningful shares [15; 16] separately. Their methods were to encrypt a secret into a cover image (the cover), and generate \(n\) meaningful shares, which were similar to the cover (the same one). Finally, the secret could be restored by stacking \(n\) shares using the XOR operation.  
[PERSON] and [PERSON] [17] proposed three new methods in 2021 to optimize XOR-based VCS with meaningful shares, which was developed by [PERSON] et al. in 2015 [16]. These methods encrypt the secret into \(n\) covers (which can all be different or the same) and generate \(n\) meaningful shares. According to the three methods, three shares of differing visual qualities are generated and the secret is revealed.  
The previous methods are suitable for black-and-white images; therefore, in order to apply the previous methods to grayscale and color images, this paper extends the capability of the algorithms in [16; 17]. Because black-and-white images are not popular nowadays, and people use grayscale and color images more often in modern society, we extended the ideas published in [16; 17] to make the XOR-based VCS more practical.  
The rest of the paper is organized as follows: Section 2 describes the studies related to our scheme, in which we explore the two methods related to the XOR-based VCS with meaningful shares. Section 3 described our proposed methods. We extended the capabilities of the algorithm proposed in [16; 17] so that we were able to encrypt a secret grayscale (or color) image into \(n\) meaningful grayscale (or color) shares that could be imported into \(n\) different camouflage images. Section 4 describes the experimental results of our scheme. Section 5 describes the correctness and security analysis of our scheme. The conclusions are stated in Section 6.