This document summarizes a research paper that proposes a secure and dynamic multi-keyword ranked search scheme over encrypted cloud data. It presents an index structure using a greedy depth-first search and a KNN algorithm to encrypt the index and queries. This allows calculating relevance scores between encrypted indexes and queries without decrypting data. The scheme supports accurate multi-keyword searches and flexible dynamic operations like updates and deletions on the document collection. Vector space models and TF-IDF are used to represent documents. Related works on searchable encryption, homomorphic encryption, and fuzzy keyword search techniques are also summarized.