Abstract: CloudComputing is a new technology that allows access to applications as utilitiesover the internet. Cloud computing environment provides a great flexibility andavailability of computing resources at a lower cost. However, it brings newsecurity concerns mainly when users understand exactly how a process isrunning. One of the main important challenges in cloud computing is datasecurity, as users need to access data they share securely. So the main problemis how to employ an effective authentication procedure for ensuring datasecurity and preventing unauthorized users to access the authorized user’sdata. This paper identifies the security issues of single level authenticationand the problem of single password. This study proposed a new security mechanismfor cloud computing based on multilevel authentication. The proposed schemeaimed to enhance the security and authentication process in cloud computing.The proposed scheme consists of three level of authentication, and the datawill be splitting on this level depending on the sensitivity to confidential(C), secret (S), and top secret (TS). Data at level (C) have the lowestsensitivity. The user at this level has single textual password to access thislevel data. The user at level (S) has two passwords, textual and biometricspassword to access this level and the lower level. User at level (TS) has threepassword textual, biometrics password and image sequencing password. The dataat this level is the more sensitive data so it is encrypted using RSA algorithmbefore storing in cloud database. The results of the proposed multilevelauthentication for cloud computing were promising.
Keywords: : Authentication,Cloud Computing, Multilevel, Security.