Freshly identified and endorsed the trend of holding cloud-based services for large scale content storage, processing, and distribution. Security is the top concerns for open cloud environments. Towards these security challenges, we propose and implement, on Open Stack Swift, a new client-side deduplication scheme for securely storing and sharing outsourced data via the public cloud. The originality of our proposal is twofold. First, it ensures better confidentiality towards unauthorized users. That is, every client computes a per data key to encrypt the data that he intends to store in the cloud. hence, data access is with the data owner. Second, by accessing rights in the metadata file, an authorized user can decipher an encrypted file only with his private key. It elaborates a computationally low-cost method for making all log entries generated prior to the logging machine's compromise impossible for the attacker to make an attempt and also impossible to undetectably modify or destroy.