SCB Mode: Semantically Secure Length-Preserving Encryption

Fabio Banfi

IACR Trans. Symm. Cryptol., Ruhr-Universität Bochum, vol. 2022, no. 4, pp. 1–23, 2022.

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.

BibTeX Citation

@article{Banfi22,
    author       = {Fabio Banfi},
    title        = {{SCB} Mode: Semantically Secure Length-Preserving Encryption},
    journal      = {{IACR} Trans. Symm. Cryptol.},
    pages        = {1--23},
    number       = {4},
    volume       = {2022},
    year         = {2022},
    publisher    = {Ruhr-Universität Bochum},
}