Abstract: Data mining, the mining of hidden predictive information from huge databases, is a powerful new technology with grand latent to help companies focus on the most vital information in their data warehouses. Data mining tools expect future trends and behaviors, allowing businesses to make positive, knowledge-driven decisions. Text classification is the method of conveying text documents based on assured categories. Due to the rising trends in the field of internet and computers, billions of text data are processed at a known time and so there is a require for systematize these data to offer easy storage and accessing .Many text classification approaches were developed for efficiently solving the difficulty of identifying and classifying these data. During the data retrieval of the classified data, privacy and security is the challenging task. In this paper, a survey on privacy and security of the classified data using classification after encryption has been discussed. A classifier is used to define the suitable class for each text document based on the input algorithm used for classification. Encryption is the procedure of encoding messages or information in such a way that only approved parties can read it, which provides high security and privacy.

Keywords: privacy of data, classifier, encryption.