International Association for Cryptologic Research

International Association
for Cryptologic Research

IACR News item: 28 July 2015

PhD Database PhD Database
Name: Dr. Y. Sreenivasa Rao
Topic: Design and Analysis of Attribute-Based Cryptosystems using Bilinear Pairings
Category: public-key cryptography

Description: Cryptosystems based on the attribute-based framework have recently acquired much\r\nimportance due to their enhanced functionality and flexibility, and\r\ntheir promising potential as a cryptographic platform for achieving advanced functionalities.\r\nHowever, attribute-based cryptosystems incur high communication and computation overheads which could impede their practical usage.\r\n%The main goal of this thesis is to design efficient and provably secure attribute-based cryptographic schemes with low communication and computation cost, using bilinear pairings.\r\nThis thesis aims at designing efficient and provably secure attribute-based cryptographic schemes allowing for expressive access policies with significantly low communication and computation cost, using bilinear pairings.\r\n\r\n The contributions of the thesis are manifold. We first propose two Key-Policy Attribute-Based Encryption (KP-ABE) schemes with constant-size ciphertext for Linear Secret-Sharing Scheme (LSSS)-realizable (monotone) access structures, supporting small universes of attributes. Among these, one scheme is Chosen Plaintext Attack (CPA) secure and the other is chosen ciphertext attack secure. We then extend these schemes to support not only the positive but also the negative attributes. Next, a CPA secure KP-ABE for large attribute universes is presented that features linear-size ciphertext and constant-size public parameters.\r\nLater, a dual-policy ABE with short ciphertext and constant-size ciphertext broadcast KP-ABE schemes are constructed.\r\n\r\n\r\n In all the aforementioned schemes, one fully trusted authority manages attributes and issues secret decryption keys to legitimate users.\r\nWe suggest a decentralized multi-authority Ciphertext-Policy ABE (dCP-ABE) for general monotone access structures. We incorporate the ciphertext access control policy in terms of minimal authorized sets in access structure, without using any secret-sharing scheme.\r\n\r\n Further, we present a key[...]
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