This document summarizes and reviews various techniques for cross-user big data deduplication. It proposes a model that performs deduplication of data for multiple users to achieve uniqueness of textual data uploaded by users while maintaining efficient data access and privacy. The model uses a fixed-size blocking algorithm and hashing algorithm to divide files into blocks, generate hash keys for each block, and perform intra-user and inter-user deduplication checking in two phases to identify and eliminate redundant data across users. It reviews related work that uses techniques like MapReduce, clustering, variable size chunking and metadata to implement parallel and application-driven deduplication.