Title: A ciphertext-policy attribute-based encryption scheme with constant ciphertext length

Authors: Keita Emura, Atsuko Miyaji, Kazumasa Omote, Akito Nomura, Masakazu Soshi

Addresses: School of Information Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan. ' School of Information Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan. ' School of Information Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan. ' Mathematics Section, Division of Innovative Technology and Science, Graduate School of Natural Science and Technology, Kanazawa University, Ishikawa 920-1192, Japan. ' Graduate School of Information Sciences, Hiroshima City University, Hiroshima 731-3194, Japan

Abstract: An Attribute-Based Encryption (ABE) is an encryption scheme where users with some attributes can decrypt ciphertexts associated with these attributes. The length of the ciphertext depends on the number of attributes in previous ABE schemes. In this paper, we propose a new Ciphertext-Policy Attribute-Based Encryption (CP-ABE) with constant ciphertext length. In our scheme, the number of pairing computations is also constant. In addition, the number of additional bits required from chosen plaintext attack-secure CP-ABE to chosen ciphertext attack-secure CP-ABE is reduced by 90% with respect to that of the previous scheme.

Keywords: CP-ABE; ciphertext policy; attribute-based encryption; constant ciphertext length; cryptography; ciphertexts; information security.

DOI: 10.1504/IJACT.2010.033798

International Journal of Applied Cryptography, 2010 Vol.2 No.1, pp.46 - 59

Available online: 01 Jul 2010 *

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