| Presentation | 2007-11-22 A Key Recovery Attack with Equivalent Keys of Stream Cipher Takanori ISOBE, Toshihiro OHIGASHI, Hidenori KUWAKADO, Masakatu MORII, |
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| PDF Download Page |  PDF download Page Link |
| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | If the ciphertexts generated from defferent keys are equivalent, these keys are called equivalent keys. In a stream cipher, since a ciphertext is generated by XORing a plaintext to a keystream, the key which generates a phase shifted keystream can also be called equivalent key. In this paper, we propose a key recovery attack using the phase shifted equivalent keys. Our attack is a new cryptanalysis method on stream ciphers. We show effectiveness of our attack by applying it to Grain v1. In Grain v1, our attack can recover an 80-bit key with time complexity of 2^<79> by using chosen IVs. This time complexity is lower than 2^<80> of exhaustive key search. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | stream cipher / Grain v1 / key recovery attack / phase shifted equivalent keys |
| Paper # | ISEC2007-110,OIS2007-82 |
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| Conference Information | |
| Committee | ISEC |
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| Conference Date | 2007/11/15(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 | ENG |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | A Key Recovery Attack with Equivalent Keys of Stream Cipher |
| Sub Title (in English) | |
| Keyword(1) | stream cipher |
| Keyword(2) | Grain v1 |
| Keyword(3) | key recovery attack |
| Keyword(4) | phase shifted equivalent keys |
| 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 | Graduate School of Engineering, Kobe University |
| 4th Author's Name | Masakatu MORII |
| 4th Author's Affiliation | Graduate School of Engineering, Kobe University |
| Date | 2007-11-22 |
| Paper # | ISEC2007-110,OIS2007-82 |
| Volume (vol) | vol.107 |
| Number (no) | 346 |
| Page | pp.pp.- |
| #Pages | 6 |
| Date of Issue | |