Cryptology ePrint Archive: Report 2020/263

FPL: White-Box Secure Block Cipher Using Parallel Table Look-Ups

Jihoon Kwon and Byeonghak Lee and Jooyoung Lee and and Dukjae Moon

Abstract: In this work, we propose a new table-based block cipher structure, dubbed $\mathsf{FPL}$, that can be used to build white-box secure block ciphers. Our construction is a balanced Feistel cipher, where the input to each round function determines multiple indices for the underlying table via a probe function, and the sum of the values from the table becomes the output of the round function. We identify the properties of the probe function that make the resulting block cipher white-box secure in terms of weak and strong space hardness against known-space and non-adaptive chosen-space attacks. Our construction, enjoying rigorous provable security without relying on any ideal primitive, provides flexibility to the block size and the table size, and permits parallel table look-ups.

We also propose a concrete instantiation of $\mathsf{FPL}$, dubbed $\mathsf{FPL}_{\mathsf{AES}}$, using (round-reduced) $\mathsf{AES}$ for the underlying table and probe functions. Our implementation shows that $\mathsf{FPL}_{\mathsf{AES}}$ provides stronger security without significant loss of efficiency, compared to existing schemes including $\mathsf{SPACE}$, $\mathsf{WhiteBlock}$ and $\mathsf{WEM}$.

Category / Keywords: secret-key cryptography / Feistel cipher, white-box security, space hardness, provable security

Original Publication (in the same form): CT-RSA 2020
DOI:
10.1007/978-3-030-40186-3_6

Date: received 26 Feb 2020

Contact author: hicalf at gmail com

Available format(s): PDF | BibTeX Citation

Version: 20200226:150106 (All versions of this report)

Short URL: ia.cr/2020/263


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