International Journal of Computer Applications (0975 – 8887) International Conference on Communication, Computing and Information Technology (ICCCMIT-2014) 25 Detection of Steganographic Intrusion in Cloud J. Anitha Ruth Asst. Professor (SrG) MCA Department SRM University A. Meenakshi Asst. Professor (Sr G) MCA Department SRM University H. Srimathi, Ph.D. Professor SRM University ABSTRACT The customer’s try to migrate the data from desktop to cloud.. The data stored in cloud is targeted by potential threat. A potential threat is caused due to malicious hacker attack or data leakage in cloud. These threats in cloud environment arises the need for providing secure and safe information security system that can protect the data that is outsourced. In this paper we propose a framework for Intrusion Detection (ID) which identifies steganographic intrusion in cloud. General Terms Security, Intrusion detection system Keywords Cloud Storage, Steganographic intrusion, IDS. 1. INTRODUCTION National Institute of Standards and Technology (NIST) defines cloud computing [1] as a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources.(e. g ) networks, servers, storage, applications and services. The key challenge to cloud computing is to ensure the safety of the data that is stored in cloud. The cloud computing infrastructure which is of multitenant architecture is exposed to several threats, such as cross site scripting vulnerabilities, database attacks like SQL injection attacks, operating system attacks like machine code injection, data leakage due to data deduplication in cloud storage services and malicious data that is transferred through covert channel communication. These threats affect the integrity, confidentiality of the data stored in cloud. To overcome these threats there are encryption methods to save guard the data that is outsourced. Encryption[2] of data protects the confidentiality of the data. But does not guaranteethat it will not be affected by potential threats such as insider attack or covert channel communication.. Hence there needs an effective mechanism to keep confidentiality of data secure and to avoid illegal access on the data stored in cloud. To handle this problem effectively there needs an intrusion detection system to monitor, analyze and detect the intrusion that affects the data in cloud storage. The Cloud Security Alliance [3] reports Top security threats that the cloud computing environment is exposed to.  Abuse and Nefarious use of cloud computing  Insecure Application programming Interface  Malicious Insiders  Shared Technology Vulnerabilities  Data loss/leakage  Account/Service and Traffic Hijacking From the above mentioned threats this paper focuses on the threat due to data leakage[4] that occurs when the data is transferred to cloud through hidden communication Steganographic communication is considered as hidden communication which can transmit malicious data into the cloud storage . The paper is organized as follows section 2 provides an overview of how steganographic intrusions affect the cloud storage. Section 3 deals with the related work on steganographic attacks on data stored in cloud. Section 4 represents a framework for the proposed IDS for detecting the steganographic intrusions in the cloud. Finally we conclude the paper and present directions for future work in section 5. 2. STEGANOGRAPHIC INTRUSION IN CLOUD STORAGE 2.1 Definition of Steganography Steganography[5] refers to a process of concealing secret data in various forms of digital media such as text,image ,audio or video. For instance, If a digital image is utilised as a medium it is consequently known as a cover-image whereas the altered image after the concealing process is called as stego-image. Steganographic method ensures security to the data stored in the cloud by means of hiding the confidential data through images, video and audio. But certain situations the steganographicmethod act as an medium for intrusion. The intrusion can be done by exploiting the secrete data which is hidden in the stego-image(ie) altered image or text.The simplest method is the intruder can attack the stego-image by replacing the Least significant bit (LSB) bit of the image. Hence the confidentiality of the data stored in the stego-image is lost. Fig 1Steganographic intrusion in Cloud Storage 2.2 Methods used in Intrusion Detection An intrusion[6] is any set of actions that endeavour to compromise the integrity, confidentiality or availability of a data. The intrusion can be detected by two methods  Misuse detection or Signature based intrusion detection  Anomaly detection. The Signature based intrusion detection [7] defines patterns or set of rules that are stored in the database to decide whether the pattern is a intruder or not. It is used to detect only the known attacks. Unknown attacks cannot be detected using signature based detection. Anomaly or Behavioural detection[8] is concerned with identifying events that appear to be anomalous with respect to normal system behaviour .It is used to detect unknown attacks Cloud Storage Steganographicint rusion