| Presentation | 2006-12-13 A Practical Key Recovery Attack against Py Takanori ISOBE, Toshihiro OHIGASHI, Hidenori KUWAKADO, Masakatu MORII, |
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| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | Biham and Seberry have submitted the stream cipher Py to the ECRYPT Stream Cipher Project (eSTREAM). A key recovery attack against Py was proposed by Wu and Preneel. In that attack, (IV sizeb-9) bytes of the key can be recovered from (IV sizeb-4)×2^<19> chosen IVs, where IV sizeb indicates the size of the IV in bytes. For 128-bit key and 128-bit IV, the essential length of the key is reduced to 72 bits with about 2^<24> chosen IVs. In this paper, we propose the key recovery attack which has two processes in addition to those of Wu and Preneel. In this attack, (IV sizeb-6) bytes of the key can be recovered from (IV sizeb-4)×2^<19> chosen IVs. For 128-bit key and 128-bit IV, the essential length of the key is reduced to 48 bits with about 2^<24> chosen IVs. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | stream cipher / Py / key recovery attack / key scheduling algorithm |
| Paper # | ISEC2006-114 |
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| Conference Information | |
| Committee | ISEC |
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| Conference Date | 2006/12/6(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Information Security (ISEC) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | A Practical Key Recovery Attack against Py |
| Sub Title (in English) | |
| Keyword(1) | stream cipher |
| Keyword(2) | Py |
| Keyword(3) | key recovery attack |
| Keyword(4) | key scheduling algorithm |
| 1st Author's Name | Takanori ISOBE |
| 1st Author's Affiliation | Graduate School of Science and Technology, Kobe University() |
| 2nd Author's Name | Toshihiro OHIGASHI |
| 2nd Author's Affiliation | Graduate School of Science and Technology, Kobe University |
| 3rd Author's Name | Hidenori KUWAKADO |
| 3rd Author's Affiliation | Faculty of Engineering, Kobe University |
| 4th Author's Name | Masakatu MORII |
| 4th Author's Affiliation | Faculty of Engineering, Kobe University |
| Date | 2006-12-13 |
| Paper # | ISEC2006-114 |
| Volume (vol) | vol.106 |
| Number (no) | 411 |
| Page | pp.pp.- |
| #Pages | 7 |
| Date of Issue | |