Key Aggregation for Data Sharing in Cloud

Abstract

Data sharing is important functionality in cloud storage .To address user concerns over potential data leaks
in cloud storage a common approach is for the data owner to encrypt all the data before uploading them to the cloud,
such that later the encrypted data may be retrieved and decrypted by those who have the decryption keys. A key
challenge to designing such encryption schemes lies in the efficient management of encryption keys. This also implies the
necessity of securely distributing to users a large number of keys for both encryption in search and user will have to
securely store the received key and submit an equally large number of keywords trapdoors to the cloud in order to
perform search over the shared data. The practical problem of privacy preserving data sharing system based on public
cloud storage which requires a data owner to distribute a large number of keys to users to enable them to access his/her
documents. By addressing this practical problem which is largely neglected in literature, we propose the novel concept
of key aggregate searchable encryption (KASE) in which data owner only need to distribute a single key to user for
sharing large number of documents and user only needs to submit a single trapdoor to the cloud for querying the shared
a large number of documents.