A Study on Privacy Preserving Searching Approaches on Encrypted Data and Open Challenging Issues in Cloud Computing Veerraju Gampala, Department of Computer Science and Engineering, & GMR Institute of Technology, Rajam, Andhra Pradesh, India, veerraju.g@gmrit.org Sreelatha Malempati, Dept. of Computer Science and Engineering, R.V.R & J.C. College of Engineering, Chowdavaram, Guntur, Andhra Pradesh, India. Abstract Cloud computing is sprouting technology as a new computing model in several commercial domains. Enormous numbers of large-scale organizations are starting shifting the information in the cloud environment. However, shifting the data to the cloud releases the organizations of the monotonous tasks of infrastructure management and also reduces maintenance costs. Nonetheless, storing the sensitive data in third-party cloud servers also involves threats to data privacy. Because of credible disclosure of data stored and switched in the cloud, data owners’ privacy, and users’ privacy, should essentially be considered when designing privacy and security techniques. Several techniques have been urbanized and used to preserve the privacy of sensitive data in the cloud environment. This survey aim to incorporate the state-of-the-art privacy preserving searching approaches employed on encrypted cloud data. The Privacy preserving requirements like integrity, confidentiality, authenticity, accountability, audit, non-repudiation, and unlinkability are presented. Moreover, privacy preserving techniques are classified into single keyword search, fuzzy keyword search, and multi- keyword search over encrypted cloud data presented in this paper. The taxnomoy of privacy preserving searching approaches diagram presented. All the presented approaches are compared using privacy preserving requirements. Furthermore, the advantages and disadvantages of the presented techniques are reported and some open challenging research issues are highlighted. Keywords privacy preserving, single keyword search, fuzzy keyword search, multi-keyword search, security, taxnomoy 1. Introduction Cloud computing is a prototypical model for facilitating ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with nominal organization effort or service provider interaction and drawing the attention of industry and academia [28]. Its great elasticity and economic cost savings are encouraging enterprises and individuals to outsource their data into the cloud. To protect data privacy, confidentiality, and data security, sensitive data like personal health records, e-mails, tax documents, photo albums, financial transactions, and so on, have to be encrypted by data owners before outsourcing to the public cloud [29]. However, the traditional plaintext keyword search data utilization service is archaic. Downloading all the data and decrypting at the data user side is trivially impractical duo to huge amount of bandwidth cost is required in cloud scale systems. The data can be easily searched and utilized, otherwise no purpose of storing data in the cloud. Thus, exploring effective and privacy preserving search over encrypted cloud data is of most prominence. International Journal of Computer Science and Information Security (IJCSIS), Vol. 14, No. 12, December 2016 294 https://sites.google.com/site/ijcsis/ ISSN 1947-5500