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Title:
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Constant size ciphertexts in threshold attribute-based encryption
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Author:
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Herranz, Javier; Laguillaumie, Fabien; Ràfols, Carla
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Abstract:
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Comunicació presentada a: PKC 2010. 13th International Conference on Practice and Theory in Public Key Cryptography, celebrada del 26 al 28 de maig de 2010 a París, França. |
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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 ciphertext-
policy attribute-based encryption scheme, the secret keys of the users de-
pend 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 Di e-Hellman (aMSE-DDH) problem. |
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Abstract:
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The work of Javier Herranz is supported by a Ramón y Cajal grant, partially
funded by the European Social Fund (ESF) of the Spanish MICINN Ministry.
Carla Ràfols holds an FPI grant of the Spanish MICINN Ministry. The work
of both these authors is partially supported by the Spanish MICINN Ministry
under project MTM2009-07694. The work of Fabien Laguillaumie is supported
by the French ANR-07-TCOM-013-04 PACE Project. |
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Subject(s):
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-Attribute-based encryption
-Provable security
-Pairings |
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Rights:
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© Springer The final publication is available at Springer via
https://doi.org/10.1007/978-3-642-13013-7_2
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Document type:
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Conference Object
Article - Accepted version |
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Published by:
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Springer
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