Secure and efficient revocable key-aggregate cryptosystem for multiple non-predefined non-disjoint aggregate sets

Pareek, Gaurav; Purushothama, B.

doi:10.1016/j.jisa.2021.102799

Cited by 2 publications

(28 citation statements)

References 15 publications

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“…Recently, Pareek and Purushothama 8 proposed a dynamic KAC which securely removes and/or adds a message class from and/or to an aggregate set. However, to preserve dynamic security, their scheme requires a large number of aggregate keys to be updated.…”

Section: Related Workmentioning

confidence: 99%

“…The work in Reference 9 is not secure as anyone can decrypt the ciphertext without the use of a legitimate aggregate key. The work in Reference 8 is dynamic but requires a large number of aggregate keys (sub‐linear in the number of aggregate keys in the cryptosystem) to be updated.…”

Section: Related Workmentioning

confidence: 99%

“…Specifically, to revoke the access capability of

𝒦_{S_{k}}

such that it can no longer decrypt data encrypted under class

i

, must require only

𝒦_{S_{k}}

to be updated. However, we stress that in all the existing KACs, 4,5 including those that claim to be dynamic, 6,7 the data owner has to update all the aggregate keys

𝒦_{S_{1}}, 𝒦_{S_{2}}, \dots, 𝒦_{S_{m}}

to revoke one data class from an aggregate set 8 . For a large value of

m

, updating all

m

aggregate keys in the system also requires

m

secure transmissions to be carried out to their respective users.…”

Section: Introductionmentioning

confidence: 99%

“…There is no KAC in the existing literature that allows the data owner to dynamically update the aggregate sets efficiently. The dynamic KACs in the existing literature either require a large number of aggregate keys in the system to be updated 8 or subject the data owner to a computation cost, which is asymptotically equivalent to the cost of setting up the whole cryptosystem all over again 6 . Our contributions in this article are summarized as follows: In this article, we propose the first dynamic KAC that enforces secure dynamic updates in the aggregate sets in time that is constant with the number of message classes and the number of aggregate keys that are already computed by the data owner.…”

Section: Introductionmentioning

confidence: 99%

“…We also analyze the theoretical and practical performance of the proposed construction. We stress that the improvement in computation and communication overhead achieved by the proposed dynamic KAC translates into a significant performance enhancement in practical access control scenarios. Many existing works on KAC 4,6,8 consider the hierarchical access control model as an important application of KAC. To appreciate the performance enhancement in dynamic updates, we implement the proposed dynamic KAC and other existing dynamic KACs to enforce dynamic hierarchical access control.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Efficient dynamic key‐aggregate cryptosystem for secure and flexible data sharing

Pareek

Maiti

2022

Concurrency and Computation

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Summary Secure and efficient enforcement of dynamic access control policies on shared data is a central problem in dynamic and scalable application scenarios, including the Internet of Things and smart cities. Key‐aggregate cryptosystem (KAC) is an efficient mechanism to delegate decryption rights of a subset of a large collection of data items to authorized users. While KAC provides an efficient solution to the problem of secure data sharing, we identify that using it to enforce continuously changing access policies is highly inefficient. In this article, we propose a novel dynamic KAC that, in addition to satisfying all key‐aggregate efficiency requirements, enforces dynamic updates to the aggregate sets with constant computation and constant communication cost. We propose a concrete construction for our dynamic KAC, prove its soundness and formal security, and analyze its theoretical and practical performance. We implement the procedures of a dynamic hierarchical key assignment scheme using the proposed as well as the existing dynamic KACs. We compare the costs of enforcing dynamic updates in large hierarchies. We conclude that the performance enhancement achieved by the proposed dynamic KAC compared to the existing KACs is even more significant in practical access control scenarios.

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Section: Related Workmentioning

confidence: 99%

Section: Related Workmentioning

confidence: 99%

“…Specifically, to revoke the access capability of

𝒦_{S_{k}}

such that it can no longer decrypt data encrypted under class

i

, must require only

𝒦_{S_{k}}

to be updated. However, we stress that in all the existing KACs, 4,5 including those that claim to be dynamic, 6,7 the data owner has to update all the aggregate keys