Publication Type

Book Chapter

Version

publishedVersion

Publication Date

2012

Abstract

One concern in using cloud storage is that the sensitive data should be confidential to the servers which are outside the trust domain of data owners. Another issue is that the user may want to preserve his/her anonymity in the sharing or accessing of the data (such as in Web 2.0 applications). To fully enjoy the benefits of cloud storage, we need a confidential data sharing mechanism which is fine-grained (one can specify who can access which classes of his/her encrypted files), dynamic (the total number of users is not fixed in the setup, and any new user can decrypt previously encrypted messages), scalable (space requirement does not depend on the number of decryptors), accountable (anonymity can be revoked if necessary) and secure (trust level is minimized). This paper addresses the problem of building a secure cloud storage system which supports dynamic users and data provenance. Previous system is based on specific constructions and does not offer all of the aforementioned desirable properties. Most importantly, dynamic user is not supported. We study the various features offered by cryptographic anonymous authentication and encryption mechanisms; and instantiate our design with verifier-local revocable group signature and identity-based broadcast encryption with constant size ciphertexts and private keys. To realize our concept, we equip the broadcast encryption with the dynamic ciphertext update feature, and give formal security guarantee against adaptive chosen-ciphertext decryption and update attacks.

Keywords

Anonymity, broadcast encryption, cloud storage, dynamicencryption, group signatures, pairings, secure provenance.

Discipline

Information Security

Research Areas

Cybersecurity

Publication

Cryptography and Security: From Theory to Applications

Editor

David Naccache

First Page

442

Last Page

464

ISBN

9783642283680

Identifier

10.1007/978-3-642-28368-0_28

Publisher

Springer

City or Country

Berlin

Copyright Owner and License

Authors

Additional URL

https://doi.org/10.1007/978-3-642-28368-0_28

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