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Lecture notes in computer science

The Key Lattice Framework for Concurrent Group Messaging

Kelong Cong, Karim Eldefrawy, Nigel Paul Smart, Ben Terner

Published Jan 1, 2024• 2 citations
Publisher
DOI
10.1007/978-3-031-54773-7_6

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Several protocols implementing attribute-based group key exchange, which allows users with certain set of attributes to establish a session key, have been proposed in recent years.However, attacks on attribute-based group key exchange in current research have been considered only in stand-alone fashion.Thus these protocols may be vulnerable when run with other protocol sessions concurrently.We treat the security of attribute-based group key exchange in the universal composability framework to ensure that a protocol remains secure when run with arbitrary protocol sessions concurrently.More specifically, we define an ideal functionality for attribute-based group key exchange first, then propose a two-round protocol based on a primitive called encapsulation policy attribute-based key encapsulation mechanism.In addition, a complete security proof of our protocol in the universal composability framework under random oracle model is given.
Several protocols implementing attribute-based group key exchange, which allows users with certain set of attributes to establish a session key, have been proposed in recent years.However, attacks on attribute-based group key exchange in current research have been considered only in stand-alone fashion.Thus these protocols may be vulnerable when run with other protocol sessions concurrently.We treat the security of attribute-based group key exchange in the universal composability framework to ensure that a protocol remains secure when run with arbitrary protocol sessions concurrently.More specifically, we define an ideal functionality for attribute-based group key exchange first, then propose a two-round protocol based on a primitive called encapsulation policy attribute-based key encapsulation mechanism.In addition, a complete security proof of our protocol in the universal composability framework under random oracle model is given. Encapsulation Policy Attribute-based Key Encapsulation Mechanism (EP-AB-KEM)The EP-AB-KEM introduced by Gorantla et al. and used by our protocol follows the framework of ciphertext policy attribute based encryption (CP-ABE).An EP-AB-KEM consists of five probabilistic polynomial time algorithm listed below.(1) Setup: inputs system security parameter and attribute universe description, then outputs system public parameters PK and system master key MK.