Affiliations: [a] Sri Venkateswara College of Engineering and Technology, Chittoor, Andhra Pradesh, India | [b] Vellore Institute of Technology, Vellore, Tamil Nadu, India
Correspondence:
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Corresponding author: P. Shanmuga Sundari, Sri Venkateswara College of Engineering and Technology, Chittoor, Andhra Pradesh, India. E-mail: sigashanmu@gmail.com.
Abstract: The recommendation system is affected with attacks when the users are given liberty to rate the items based on their impression about the product or service. Some malicious user or other competitors’ try to inject fake rating to degrade the item’s graces that are mostly adored by several users. Attacks in the rating matrix are not executed just by a single profile. A group of users profile is injected into rating matrix to decrease the performance. It is highly complex to extract the fake ratings from the mixture of genuine profile as it resides the same pattern. Identifying the attacked profile and the target item of the fake rating is a challenging task in the big data environment. This paper proposes a unique method to identify the attacks in collaborating filtering method. The process of extracting fake rating is carried out in two phases. During the initial phase, doubtful user profile is identified from the rating matrix. In the following phase, the target item is analysed using push attack count to reduce the false positive rates from the doubtful user profile. The proposed model is evaluated with detection rate and false positive rates by considering the filler size and attacks size. The experiment was conducted with 6%, 8% and 10% filler sizes and with different attack sizes that ranges from 0%–100%. Various classification techniques such as decision tree, logistic regression, SVM and random forest methods are used to classify the fake ratings. From the results, it is witnessed that SVM model works better with random and bandwagon attack models at an average of 4% higher accuracy. Similarly the decision tree method performance better at an average of 3% on average attack model.
Keywords: Recommendation system, fake ratings, malicious user, various classification techniques, D_SVM, unbalanced data
