Data mining is becoming an increasingly important technology for the information society. Due to limited computational resources of data owners and the prevalence of cloud computing, outsourced data mining is becoming more and more attractive. The privacy and security issues are becoming outstanding recently. Though the existing model of cloud computing consists of multiple data owners, there is little consideration for the collaboration between them. However, such collaboration is necessary with the trend of data partition among different entities now-a-days. Besides, most of the existing work is based on the semi-honest cloud assumption and cannot deal with the malicious cloud situation well.