Paper Info
Title
Improvement on a Masked White-box Cryptographic Implementation.
Abstract
White-box cryptography is a software technique to protect secret keys of cryptographic algorithms from attackers who have access to memory. By adapting techniques of differential power analysis to computation traces consisting of runtime information, Differential Computation Analysis (DCA) has recovered the secret keys from white-box cryptographic implementations. In order to thwart DCA, a masked white-box implementation was suggested. It was a customized masking technique that randomizes all the values in the lookup tables with different masks. However, the round output was only permuted by byte encodings, not protected by masking. This is the main reason behind the success of DCA variants on the masked white-box implementation. In this paper, we improve the masked white-box cryptography in such a way to protect against DCA variants by obfuscating the round output with random masks. Specifically, we introduce a white-box AES (WB-AES) implementation applying the masking technique to the key-dependent intermediate value and the several outer-round outputs computed by partial bits of the key. Our analysis and experimental results show that the proposed WB-AES can protect against DCA variants including DCA with a 2-byte key guess, collision, and bucketing attacks. This work requires approximately 3.7 times the table size and 0.7 times the number of lookups compared to the previous masked WB-AES.
Year
DOI
Venue
2020
10.1109/ACCESS.2020.2993651
IEEE ACCESS
Keywords
DocType
Volume
Encoding,Correlation,Software,Encryption,Licenses,White-box cryptography,AES,DCA,collision attack,bucketing attack,countermeasure
Journal
8
ISSN
Citations 
PageRank 
2169-3536
0
0.34
References 
Authors
0
2
Name
Order
Citations
PageRank
Seungkwang Lee100.68
Myung-Chul Kim266557.05