The Cloud environment, with its extensive resources has become a good choice for organizations to keep their data and access it on demand. When the organization's need is to just upload their data and use it as and when required from the cloud, the cloud service itself encrypts that data with its own credentials or in some cases, for maintaining the confidentiality, the data owners encrypt their data prior to outsourcing it. But there is no provision for processing some data within the cloud

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... ironment and at the same time maintain data confidentiality and privacy of user query. As a consequence, for classification, either the data needs to be decrypted by the cloud at some point of time and then processed to take proper classification decision or the data owner has no choice but to perform the same task at his/ her end partially or fully. Since the data used for classification is encrypted and placed onto a cloud, the conventional privacy preserving classification methods are not suitable. Some recent work has been done in this direction, but it is proven to be computationally costly and also not very practical. Our proposed system is an effort towards resolving this very problem of classifying encrypted user queries over encrypted data in a more effective and time efficient manner. This is achieved redesigning the existing privacy preserving protocol from a different perspective and by leveraging the properties of homomorphic cryptosystem. Our approach is computationally inexpensive and does not compromise the privacy of user query or the confidentiality of the database outsourced by the data owner.