In the area of cloud computing, data deduplication enables the cloud server to store a single copy of data by eliminating redundant files to improve storage and network efficiency. Proof-of-Ownership (PoW) is a cryptographic function that verifies the user who really owns the data. Most of the existing schemes have tried to solve the deduplication problem by providing the same encryption key for identical data. However, these schemes suffer from dynamic changes in ownership management. In this paper, we propose a In-line Block Matching (IBM) protocol based on zero-knowledge proof for deduplication with dynamic ownership management, which eliminates the unauthorized access of sensitive data.In this proposed work, for a new file, the uploader randomly chooses a file encryption key and encrypts the file. The user also computes a unique proof for the uploaded file by dividing the file into number of blocks and stores this proof to the cloud server. The cloud server computes the group key for the ciphertext and re-encrypts it using this group key.The cloud server also does the proof verification against the subsequent uploader for an existing file. The cloud server is honest-but-curious, so the proposed scheme confirms that the cloud server does not know any information about file encryption key even though it plays a proxy role. The result shows that our proposed scheme protects the data from both cloud server and adversaries. Also the computational cost is comparatively less than other existing schemes.