| Presentation | 2023-03-13 Improvement of Linear Approximations in Differential Linear Analysis of Stream Cipher ChaCha Atsuki Nagai, Atsuko Miyaji, |
|---|---|
| PDF Download Page |  PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | ChaCha, a stream cipher, is the successor to Salsa20, which is also a stream cipher, and is the only cipher adopted in TLS 1.3. Therefore, the security analysis of ChaCha is one of the most important issues. In this study, we focus on the linear approximation of ChaCha required for differential-linear cryptanalysis and present a linear approximation that corrects errors in existing papers. We also generalized the linear approximation by using the corrected linear approximation. Then, we compared the theoretical and experimental values of the bias of the linear approximation. This clarifies the linear approximation obtained from the structure of ChaCha, and contributes to the construction of more secure cryptography. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | stream cipher / ChaCha / differential-linear cryptanalysis / linear approximation |
| Paper # | ICSS2022-70 |
| Date of Issue | 2023-03-06 (ICSS) |
| Conference Information | |
| Committee | ICSS / IPSJ-SPT |
|---|---|
| Conference Date | 2023/3/13(2days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | Okinawaken Seinenkaikan |
| Topics (in Japanese) | (See Japanese page) |
| Topics (in English) | Security, Trust, etc. |
| Chair | Katsunari Yoshioka(Yokohama National Univ.) |
| Vice Chair | Takahiro Kasama(NICT) / Akira Yamada(KDDI labs.) |
| Secretary | Takahiro Kasama(Okayama Univ.) / Akira Yamada(Mitsubishi Electric) |
| Assistant | Takeshi Sugawara(Univ. of Electro-Comm.) / Yo Kanemoto(NTT) |
| Paper Information | |
| Registration To | Technical Committee on Information and Communication System Security / Special Interest Group on Security Psychology and Trust |
|---|---|
| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Improvement of Linear Approximations in Differential Linear Analysis of Stream Cipher ChaCha |
| Sub Title (in English) | |
| Keyword(1) | stream cipher |
| Keyword(2) | ChaCha |
| Keyword(3) | differential-linear cryptanalysis |
| Keyword(4) | linear approximation |
| 1st Author's Name | Atsuki Nagai |
| 1st Author's Affiliation | Osaka University(Osaka Univ.) |
| 2nd Author's Name | Atsuko Miyaji |
| 2nd Author's Affiliation | Osaka University/Japan Advanced Institute of Science and Technology(Osaka Univ./JAIST) |
| Date | 2023-03-13 |
| Paper # | ICSS2022-70 |
| Volume (vol) | vol.122 |
| Number (no) | ICSS-422 |
| Page | pp.pp.133-138(ICSS), |
| #Pages | 6 |
| Date of Issue | 2023-03-06 (ICSS) |