Barbosa, Manuel and Farshim, Pooya (2018) Indifferentiable Authenticated Encryption. In: Shacham, H. and Boldyreva, A., (eds.) Advances in Cryptology – CRYPTO 2018. , pp. 187-220.
Abstract
We study Authenticated Encryption with Associated Data (AEAD) from the viewpoint of composition in arbitrary (single-stage) environments. We use the indifferentiability framework to formalize the intuition that a “good” AEAD scheme should have random ciphertexts subject to decryptability. Within this framework, we can then apply the indifferentiability composition theorem to show that such schemes offer extra safeguards wherever the relevant security properties are not known, or cannot be predicted in advance, as in general-purpose crypto libraries and standards. We show, on the negative side, that generic composition (in many of its configurations) and well-known classical and recent schemes fail to achieve indifferentiability. On the positive side, we give a provably indifferentiable Feistel-based construction, which reduces the round complexity from at least 6, needed for blockciphers, to only 3 for encryption. This result is not too far off the theoretical optimum as we give a lower bound that rules out the indifferentiability of any construction with less than 2 rounds.
Metadata
Item Type: | Proceedings Paper |
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Authors/Creators: |
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Editors: |
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Copyright, Publisher and Additional Information: | This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details. |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Computer Science (York) |
Depositing User: | Pure (York) |
Date Deposited: | 21 Nov 2019 09:40 |
Last Modified: | 16 Oct 2024 11:06 |
Published Version: | https://doi.org/10.1007/978-3-319-96884-1_7 |
Status: | Published |
Identification Number: | 10.1007/978-3-319-96884-1_7 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:153479 |