CERTIFICATELESS ENCRYPTION FOR SECURE DATA SHARING IN PUBLIC CLOUD

Abstract

Cloud computing is more popular in organizations and institutions because it provides storage and computing services at low cost. Cloud computing provide users and enterprises with various capabilities to store and process their data in third-party data centers that may be located far from the user ranging in distance from across a city to across the world. However, it also introduces new challenges for ensuring the confidentiality, integrity and access control of the data. Some approaches are given to ensure these security requirements but they are lacked in some ways such as violation of data confidentiality due to collusion attack and heavy computation (due to large no keys).To address these issues we propose a scheme that uses efficient certificate less in which data owner divides users in groups and gives single key to each user group for decryption of data and, each user in the group shares parts of the key. Certificateless cryptography is a Capricious of ID-based cryptography intended to prevent the key escrow problem. Ordinarily, keys are generated by a certificate authority or a key generation center (KGC) who is given complete power and is implicitly trusted. For prevention of a complete breakdown of the system in the case of a compromised KGC, the key generation process (KGP) is split between the KGC and the user. In this paper, we use capability list and access list to control the access. Authentication and access control are often merged into a single operation, so that access is approved based on successful authentication or based on an anonymous access token. This scheme not only provides the strong data confidentiality but also reduces the number of keys. Key words- capability list, authentication, certificateless cryptography, confidentiality, access control, malicious outsiders