隨著智慧型裝置的興起與普及，人們越來越容易利用手邊的行動裝置將眼前的景物拍攝下來並透過行動網路將這些圖像上傳到雲端儲存裝置。在今日，雲端儲存裝置廣泛的被用來存放許多個人的多媒體影像，然而，這些上傳在網路上的私人影像大多被存在公開網域中，因此他們存在著許多潛在的風險，例如：影像資料外洩、竄改。為了能夠避免這些潛在的問題，我們提出一套有效的系統，整合了不可視的數位浮水印和影像遮罩的技術並利用直方圖偏移的方法加以實踐。這種基於直方圖修改的影像處理是一種可回復的資料隱藏方式，而且我們能用以確保影像資料的完整性和機密性。此外，我們利用秘密共享將原有的金鑰拆解成數把密鑰並儲存在不同的IP區域，用來加強反解時存取密鑰的安全性。最後，我們展示了實驗的結果，證明本篇所提出的系統確實能有效的避免外部惡意的使用者存取，並成功的保護私人的影像資料。

Nowadays people can easily use any smart device at hand to capture scenery and then upload it to the cloud storage. Cloud storages are widely used for storing the generated multimedia content. However, the risk of potential private data leakage may exist since cloud storages are normally in a public domain. To enhance the security and privacy of images on the cloud storage, we proposed an integrated scheme evolving invisible digital watermarking and masking which are based on the histogram shifting method. The histogram modification based scheme can achieve reversible data hiding, to ensure the integrity and the confidentiality of the image data. Additionally, we use the secret sharing scheme to keep the secret keys to further improve the security of data access. The evaluation results show that the proposed system can effectively prevent the malicious user from accessing the private images.

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