Review on Designing Security for Cloud Storage Using Key Aggregate Cryptosystem

Abstract

Data sharing is an important functionality in cloud storage. Cloud computing is a recently
developing technology which can be used to access and store data easily. Cloud storage will provide good
reliability and lowest cost. Its functionality is sharing data with other users securely, efficiently and flexibly
in cloud environment. We introduce a special type of public key encryption called as Key Aggregate
cryptosystem (KAC). In KAC user encrypts message with public key and also with an identifier of cipher
text. In KAC any set of secret keys can be aggregated and made them as single key. key cryptosystem
produces constant size cipher texts and user can aggregate any set of secret keys and make them as compact
as single and can decrypt any set of cipher texts by using that compact aggregate key but, files outside the
set remain confidential. In this cryptosystem it is possible to efficiently assign decryption rights for the set
of cipher texts to any users. The secret key holder can release a constant-size aggregate key for set of cipher
texts and this compact aggregate key conveniently shared with others with very limited secure storage.