Multi-Owner Data Sharing in Cloud Storage Using Policy Based Encryption

Cloud storages are generally hosted by third parties where data can be stored and shared. Cloud storage provides virtualized pools of storage and people buy or lease storage capacity from them. The security of data is major problem when people use commercial cloud services to store their data. To avoid unauthorized access, data should be encrypted before outsourcing. Instead of attribute based encryption, role based policies can be generated and based on that policies encryption can be done. In the case of data with multiple owners, the access control, integrity and revocation are major issues. All the owners must have same access policy and revocation should be done with the permission of all owners. Another major issue is key generation and management. Here we explore a policy based encryption technique where access key generation for user is based on access policies assigned to each user along with the attributes. The data stored in the cloud is encrypted using a key generated based on the access permissions assigned to the data and attributes of the owners who share their data with high security and integrity using policy based encryption