Large amounts of information being generated in real time in a distributed environment due to recent development of cloud services such as SaaS, etc. is stored and managed in a database and is shared by users. But because the sensitive information of an individual is included in this information, the privacy damage by illegal utilization is worried. As the sensitive information is linked with specific individuals, this privacy damage is generated, so its anonymity, namely, unlinkability should be provided to solve this. Currently, the method of V. Ciriani, etc. for guaranteeing data privacy such as unlinkability, etc. is solving the unlinkability problem by using fragmentation and encryption. But this method includes a problem that the database capacity increases due to duplicate encryption data of attributes caused by fragmentation. This paper proposes a privacy enforcing method based on AONT to solve this problem. The proposed method is suitable for large data processing through variability of transformed pieces according to AONT properties and an XOR operation and can minimize the increase of database capacity.