Multi-Cloud Environment Cryptosystem for Data Sharing

Abstract

Secure data exchange is an important feature in cloud storage. In this paper, we show how to provide two-stage security, here the cryptographic data is the first phase and the division is another phase. Provides shared data securely, efficiently and flexibly with others in multiple cloud storage using an aggregated cryptosystem. We describe new public-key cryptosystems that produce encrypted texts of constant size, so that an effective delegation of decryption rights is possible for any set of encrypted texts that decrypted files are split and stored in different clouds for security reasons. The novelty is that you can add any set of secret keys and make them compact as a single key, but by understanding the power of all the keys that are added. In other words, the secret key holder can issue an aggregate key of constant size for flexible options of encrypted text sets in the cloud storage, but the other encrypted files outside the set remain confidential. This compact aggregate key can be conveniently sent to others or stored on a smart card with very limited secure storage space. We offer formal security analysis of our schemes in the standard model. We also describe other applications of our schemes. In particular, our schemes provide the first patient-controlled cryptography of the public key for a flexible hierarchy that was not yet known.

Keywords: Authentication, Data accessing, Key gathering, Multi-cloud storage.

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