Abstract: In this era, Cloud Computing is gaining more importance. Cloud computing provides different services on demand. Due to this more and more data owners are interested to store data on cloud. Cloud computing is a model for on-demand access to a shared pool of configurable computing resources. However, for storing sensitive information, Encryption should be done. So encryption is performed before outsourcing the sensitive data. The data present in the cloud is in encrypted format so searching for appropriate documents is difficult. In this paper, we present Multi-keyword ranked search scheme over encrypted cloud data. Vector space model and TF X IDF model is used for index construction and query generation. Tree based index structure is constructed and “Greedy Depth-first search” algorithm is used for efficient search results. The Secure kNN is used to encrypt index and query vector.

Keywords: Cloud Computing, Cryptography, Multi-keyword ranked search, Searchable encryption.