Browsing by Author "Fahmy Tolba, Mohamed"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    A Large Dataset Enhanced Watermarking Service for Cloud Environments
    (Springer, Cham, 11/28/2014) Zawawi, Nour; Hamdy, Mohamed; El-Gohary, Rania; Fahmy Tolba, Mohamed
    Preventing data abuses in cloud remains an essential point of the research. Proving the integrity and non-repudiation for large datasets over the cloud has an increasing attention of database community. Having security services based on watermarking techniques that enable permanent preservation for data tuples in terms of integrity and recovery for cloud environments presents the milestone of establishing trust between the data owners and the database cloud services. In this paper, an enhanced secure database service for Cloud environments (EWRDN) is proposed. It based over enhancements on WRDN as a data watermarking approach. The proposed service guarantees data integrity, privacy, and non-repudiation recovering data to its origin. Moreover, it gives data owner more controlling capabilities for their data by enabling tracing users’ activities. Two compression categories to recover data to its origin introduced for the proposed service. Two compression technique (the arithmetic encoding and the transform encoding) chosen to represent each type. For large data sets, it has been proven that, the arithmetic encoding has a fixed recovery ratio equal to one. At the same time, the transform encoding saves space and consumed less time to recover data. Moreover, testing the performance is done of the proposed service versus a large number of tuples, large data set. The performance quantified in terms of processing time and the required memory resources. The enhanced EWRDN service has shown a good performance in our experiments.
  • Thumbnail Image
    Item
    A Novel Watermarking Approach for Data Integrity and Non-repudiation in Rational Databases
    (Springer, Berlin, Heidelberg, 12/08/2012) Zawawi, Nour; El-Gohary, Rania; Hamdy, Mohamed; Fahmy Tolba, Mohamed
    Keepinglarge scale data sets like data warehouse seems a vital demand of business organizations. Proving copyright, ownership, integrity and non-repudiation have a growing interest of database community. Many watermarking techniques have been proposed in the literature to address these purposes. This paper introduces a new technique WRDN (Watermarking Rational Database with Non-Repudiation) to protect the ownership of relational database by adding only one hidden column with a secret formula where it has the ability to know the latest updates made by users. The calculation of this formula is based on the values of other numeric and textual columns. Moreover, the proposed approach keeps track on the latest updates made to numeric and textual data by users. This approach is compared to two other alternative approaches. The proposed approach survives by 100% against insertion and deletion attacks.