SCB Mode: Semantically Secure Length-Preserving Encryption

Fabio Banfi

Paper 2022/1702

SCB Mode: Semantically Secure Length-Preserving Encryption

Fabio Banfi

, ETH Zurich

Abstract

To achieve semantic security, symmetric encryption schemes classically require ciphertext expansion. In this paper we provide a means to achieve semantic security while preserving the length of messages at the cost of mildly sacrificing correctness. Concretely, we propose a new scheme that can be interpreted as a secure alternative to (or wrapper around) plain Electronic Codebook (ECB) mode of encryption, and for this reason we name it Secure Codebook (SCB). Our scheme is the first length-preserving encryption scheme to effectively achieve semantic security.

Metadata

Available format(s): PDF
Category: Secret-key cryptography
Publication info: Published by the IACR in TOSC 2022
DOI: 10.46586/tosc.v2022.i4.1-23
Keywords: SCB secure codebook semantic security length-preserving encryption
Contact author(s): fabio banfi @ inf ethz ch
History: 2022-12-10: approved; 2022-12-08: received; See all versions
Short URL: https://ia.cr/2022/1702
License: CC BY

BibTeX

@misc{cryptoeprint:2022/1702,
      author = {Fabio Banfi},
      title = {SCB Mode: Semantically Secure Length-Preserving Encryption},
      howpublished = {Cryptology ePrint Archive, Paper 2022/1702},
      year = {2022},
      doi = {10.46586/tosc.v2022.i4.1-23},
      note = {\url{https://eprint.iacr.org/2022/1702}},
      url = {https://eprint.iacr.org/2022/1702}
}