Paper 2014/793
Robust Authenticated-Encryption: AEZ and the Problem that it Solves
Viet Tung Hoang, Ted Krovetz, and Phillip Rogaway
Abstract
With a scheme for \textit{robust} authenticated-encryption a user can select an arbitrary value $\lambda \ge 0$ and then encrypt a plaintext of any length into a ciphertext that's $\lambda$ characters longer. The scheme must provide all the privacy and authenticity possible for the requested~$\lambda$. We formalize and investigate this idea, and construct a well-optimized solution, AEZ, from the AES round function. Our scheme encrypts strings at almost the same rate as OCB-AES or CTR-AES (on Haswell, AEZ has a peak speed of about 0.7 cpb). To accomplish this we employ an approach we call \textit{prove-then-prune}: prove security and then instantiate with a \textit{scaled-down} primitive (e.g., reducing rounds for blockcipher calls).
Metadata
- Available format(s)
-
PDF
- Category
- Secret-key cryptography
- Publication info
- A minor revision of an IACR publication in EUROCRYPT 2015
- Keywords
- AEZarbitrary-input blockciphersauthenticated encryptionrobust AEmisuse resistancenonce reuseCAESAR competitionblockcipher modesprovable securitysymmetric encryption
- Contact author(s)
- hviettung @ gmail com
- History
- 2017-03-31: last of 3 revisions
- 2014-10-10: received
- See all versions
- Short URL
- https://ia.cr/2014/793
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2014/793,
author = {Viet Tung Hoang and Ted Krovetz and Phillip Rogaway},
title = {Robust Authenticated-Encryption: {AEZ} and the Problem that it Solves},
howpublished = {Cryptology {ePrint} Archive, Paper 2014/793},
year = {2014},
url = {https://eprint.iacr.org/2014/793}
}
