Multidimensional Linear Cryptanalysis of Feistel Ciphers
This paper presents new generic attacks on Feistel ciphers that incorporate the key addition at the input of the non-invertible round function only. This feature leads to a specific vulnerability that can be exploited using multidimensional linear cryptanalysis. More specifically, our approach invo...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Ruhr-Universität Bochum
2023-12-01
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| Series: | IACR Transactions on Symmetric Cryptology |
| Subjects: | |
| Online Access: | https://tosc.iacr.org/index.php/ToSC/article/view/11277 |
| Summary: | This paper presents new generic attacks on Feistel ciphers that incorporate the key addition at the input of the non-invertible round function only. This feature leads to a specific vulnerability that can be exploited using multidimensional linear cryptanalysis. More specifically, our approach involves using key-independent linear trails so that the distribution of a combination of the plaintext and ciphertext can be computed. This makes it possible to use the likelihood-ratio test as opposed to the χ2 test. We provide theoretical estimates of the cost of our generic attacks and verify these experimentally by applying the attacks to CAST-128 and LOKI91. The theoretical and experimental findings demonstrate that the proposed attacks lead to significant reductions in data-complexity in several interesting cases.
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| ISSN: | 2519-173X |