### 抄録

As pervasive computing environments become popular, RFID devices, such as contactless smart cards and RFID tags, are introduced into our daily life. However, there exists a privacy problem that a third party can trace user's behavior by linking device's ID. The concept of unlinkability, that a third party cannot recognize whether some outputs are from the same user, is important to solve the privacy problem. A scheme using hash function satisfies unlinkability against a third party by changing the outputs of RFID devices every time. However, the schemes are not scalable since the server needs O(N) hash calculations for every ID matching, where N is the number of RFID devices. In this paper, we propose the K-steps ID matching scheme, which can reduce the number of the hash calculations on the server to O(log N). Secondly, we propose a quantification of unlinkability using conditional entropy and mutual information. Finally, we analyze the K-steps ID matching scheme using the proposed quantification, and show the relation between the time complexity and unlinkability.

元の言語 | 英語 |
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ホスト出版物のタイトル | WPES'05 |

ホスト出版物のサブタイトル | Proceedings of the 2005 ACM Workshop on Privacy in the Electronic Society |

ページ | 55-60 |

ページ数 | 6 |

出版物ステータス | 出版済み - 12 1 2005 |

イベント | WPES'05: 2005 ACM Workshop on Privacy in the Electronic Society - Alexandria, VA, 米国 継続期間: 11 7 2005 → 11 7 2005 |

### 出版物シリーズ

名前 | WPES'05: Proceedings of the 2005 ACM Workshop on Privacy in the Electronic Society |
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### その他

その他 | WPES'05: 2005 ACM Workshop on Privacy in the Electronic Society |
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国 | 米国 |

市 | Alexandria, VA |

期間 | 11/7/05 → 11/7/05 |

### Fingerprint

### All Science Journal Classification (ASJC) codes

- Engineering(all)

### これを引用

*WPES'05: Proceedings of the 2005 ACM Workshop on Privacy in the Electronic Society*(pp. 55-60). (WPES'05: Proceedings of the 2005 ACM Workshop on Privacy in the Electronic Society).

**Quantitative evaluation of unlinkable ID matching schemes.** / Nohara, Yasunobu; Inoue, Sozo; Baba, Kensuke; Yasuura, Hiroto.

研究成果: 著書/レポートタイプへの貢献 › 会議での発言

*WPES'05: Proceedings of the 2005 ACM Workshop on Privacy in the Electronic Society.*WPES'05: Proceedings of the 2005 ACM Workshop on Privacy in the Electronic Society, pp. 55-60, WPES'05: 2005 ACM Workshop on Privacy in the Electronic Society, Alexandria, VA, 米国, 11/7/05.

}

TY - GEN

T1 - Quantitative evaluation of unlinkable ID matching schemes

AU - Nohara, Yasunobu

AU - Inoue, Sozo

AU - Baba, Kensuke

AU - Yasuura, Hiroto

PY - 2005/12/1

Y1 - 2005/12/1

N2 - As pervasive computing environments become popular, RFID devices, such as contactless smart cards and RFID tags, are introduced into our daily life. However, there exists a privacy problem that a third party can trace user's behavior by linking device's ID. The concept of unlinkability, that a third party cannot recognize whether some outputs are from the same user, is important to solve the privacy problem. A scheme using hash function satisfies unlinkability against a third party by changing the outputs of RFID devices every time. However, the schemes are not scalable since the server needs O(N) hash calculations for every ID matching, where N is the number of RFID devices. In this paper, we propose the K-steps ID matching scheme, which can reduce the number of the hash calculations on the server to O(log N). Secondly, we propose a quantification of unlinkability using conditional entropy and mutual information. Finally, we analyze the K-steps ID matching scheme using the proposed quantification, and show the relation between the time complexity and unlinkability.

AB - As pervasive computing environments become popular, RFID devices, such as contactless smart cards and RFID tags, are introduced into our daily life. However, there exists a privacy problem that a third party can trace user's behavior by linking device's ID. The concept of unlinkability, that a third party cannot recognize whether some outputs are from the same user, is important to solve the privacy problem. A scheme using hash function satisfies unlinkability against a third party by changing the outputs of RFID devices every time. However, the schemes are not scalable since the server needs O(N) hash calculations for every ID matching, where N is the number of RFID devices. In this paper, we propose the K-steps ID matching scheme, which can reduce the number of the hash calculations on the server to O(log N). Secondly, we propose a quantification of unlinkability using conditional entropy and mutual information. Finally, we analyze the K-steps ID matching scheme using the proposed quantification, and show the relation between the time complexity and unlinkability.

UR - http://www.scopus.com/inward/record.url?scp=33749005411&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33749005411&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:33749005411

SN - 1595932283

SN - 9781595932280

T3 - WPES'05: Proceedings of the 2005 ACM Workshop on Privacy in the Electronic Society

SP - 55

EP - 60

BT - WPES'05

ER -