One area of research in information security is Intrusion Detection Systems (IDSs), which are installed on target systems and tracks the indication of attacks. Since, intrusion detection systems for attack detection, need to information collection and analysis, concerns about the disclosure of individuals and systems and/or disclosure sensitive information of them exist. Therefore, despite the use of IDSs, the authors deal with a privacy violation. One of the issues of privacy in Network Intrusion Detection Systems (NIDSs) is that several organizations wish to collaborate together to prevent the penetration of their sites. To achieve this, they share normal and attack data of their IDSs.