Title:
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Constant size ciphertexts in threshold attribute-based encryption
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Author:
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Herranz Sotoca, Javier; Laguillaumie, Fabien; Ràfols Salvador, Carla
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Other authors:
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Universitat Politècnica de Catalunya. Departament de Matemàtica Aplicada IV; Universitat Politècnica de Catalunya. MAK - Matemàtica Aplicada a la Criptografia |
Abstract:
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Attribute-based cryptography has emerged in the last years as a promising primitive for digital security. For instance, it provides good solutions to the problem of anonymous access control. In a ciphertextpolicy attribute-based encryption scheme, the secret keys of the users depend on their attributes. When encrypting a message, the sender chooses which subset of attributes must be held by a receiver in order to be able to decrypt.
All current attribute-based encryption schemes that admit reasonably expressive decryption policies produce ciphertexts whose size depends at least linearly on the number of attributes involved in the policy. In this paper we propose the first scheme whose ciphertexts have constant size.
Our scheme works for the threshold case: users authorized to decrypt are those who hold at least t attributes among a certain universe of attributes, for some threshold t chosen by the sender. An extension to the
case of weighted threshold decryption policies is possible. The security of the scheme against selective chosen plaintext attacks can be proven in the standard model by reduction to the augmented multi-sequence of exponents decisional Diffie-Hellman (aMSE-DDH) problem. |
Subject(s):
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-Àrees temàtiques de la UPC::Informàtica::Seguretat informàtica::Criptografia -Coding theory -Information theory -Informació, Teoria de la -Codificació, Teoria de la -Classificació AMS::94 Information And Communication, Circuits::94A Communication, information |
Rights:
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Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Document type:
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Article - Published version Conference Object |
Published by:
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Springer Verlag
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