### Abstract

Consider two parties holding samples from correlated distributions W and W′, respectively, where these samples are within distance t of each other in some metric space. The parties wish to agree on a close-to-uniformly distributed secret key R by sending a single message over an insecure channel controlled by an all-powerful adversary who may read and modify anything sent over the channel. We consider both the keyless case, where the parties share no additional secret information, and the keyed case, where the parties share a long-term secret {\ssr SK _{Ext} that they can use to generate a sequence of session keys {R _{j}} using multiple pairs {(W _{j}, W′ _{j})}. The former has applications to, e.g., biometric authentication, while the latter arises in, e.g., the bounded-storage model with errors. We show solutions that improve upon previous work in several respects. 1) The best prior solution for the keyless case with no errors (i.e., t=0) requires the min-entropy of W to exceed 2n/3 , where n is the bit length of W. Our solution applies whenever the min-entropy of W exceeds the minimal threshold n/2, and yields a longer key. 2) Previous solutions for the keyless case in the presence of errors (i.e., t < 0) required random oracles. We give the first constructions (for certain metrics) in the standard model. 3) Previous solutions for the keyed case were stateful. We give the first stateless solution.

Original language | English (US) |
---|---|

Article number | 6203415 |

Pages (from-to) | 6207-6222 |

Number of pages | 16 |

Journal | IEEE Transactions on Information Theory |

Volume | 58 |

Issue number | 9 |

DOIs | |

State | Published - 2012 |

### Fingerprint

### Keywords

- Fuzzy extractors
- information reconciliation
- information-theoretic cryptography
- key-agreement
- weak secrets

### ASJC Scopus subject areas

- Information Systems
- Computer Science Applications
- Library and Information Sciences

### Cite this

*IEEE Transactions on Information Theory*,

*58*(9), 6207-6222. [6203415]. https://doi.org/10.1109/TIT.2012.2200290

**Robust fuzzy extractors and authenticated key agreement from close secrets.** / Dodis, Yevgeniy; Kanukurthi, Bhavana; Katz, Jonathan; Reyzin, Leonid; Smith, Adam.

Research output: Contribution to journal › Article

*IEEE Transactions on Information Theory*, vol. 58, no. 9, 6203415, pp. 6207-6222. https://doi.org/10.1109/TIT.2012.2200290

}

TY - JOUR

T1 - Robust fuzzy extractors and authenticated key agreement from close secrets

AU - Dodis, Yevgeniy

AU - Kanukurthi, Bhavana

AU - Katz, Jonathan

AU - Reyzin, Leonid

AU - Smith, Adam

PY - 2012

Y1 - 2012

N2 - Consider two parties holding samples from correlated distributions W and W′, respectively, where these samples are within distance t of each other in some metric space. The parties wish to agree on a close-to-uniformly distributed secret key R by sending a single message over an insecure channel controlled by an all-powerful adversary who may read and modify anything sent over the channel. We consider both the keyless case, where the parties share no additional secret information, and the keyed case, where the parties share a long-term secret {\ssr SK Ext that they can use to generate a sequence of session keys {R j} using multiple pairs {(W j, W′ j)}. The former has applications to, e.g., biometric authentication, while the latter arises in, e.g., the bounded-storage model with errors. We show solutions that improve upon previous work in several respects. 1) The best prior solution for the keyless case with no errors (i.e., t=0) requires the min-entropy of W to exceed 2n/3 , where n is the bit length of W. Our solution applies whenever the min-entropy of W exceeds the minimal threshold n/2, and yields a longer key. 2) Previous solutions for the keyless case in the presence of errors (i.e., t < 0) required random oracles. We give the first constructions (for certain metrics) in the standard model. 3) Previous solutions for the keyed case were stateful. We give the first stateless solution.

AB - Consider two parties holding samples from correlated distributions W and W′, respectively, where these samples are within distance t of each other in some metric space. The parties wish to agree on a close-to-uniformly distributed secret key R by sending a single message over an insecure channel controlled by an all-powerful adversary who may read and modify anything sent over the channel. We consider both the keyless case, where the parties share no additional secret information, and the keyed case, where the parties share a long-term secret {\ssr SK Ext that they can use to generate a sequence of session keys {R j} using multiple pairs {(W j, W′ j)}. The former has applications to, e.g., biometric authentication, while the latter arises in, e.g., the bounded-storage model with errors. We show solutions that improve upon previous work in several respects. 1) The best prior solution for the keyless case with no errors (i.e., t=0) requires the min-entropy of W to exceed 2n/3 , where n is the bit length of W. Our solution applies whenever the min-entropy of W exceeds the minimal threshold n/2, and yields a longer key. 2) Previous solutions for the keyless case in the presence of errors (i.e., t < 0) required random oracles. We give the first constructions (for certain metrics) in the standard model. 3) Previous solutions for the keyed case were stateful. We give the first stateless solution.

KW - Fuzzy extractors

KW - information reconciliation

KW - information-theoretic cryptography

KW - key-agreement

KW - weak secrets

UR - http://www.scopus.com/inward/record.url?scp=84865393678&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84865393678&partnerID=8YFLogxK

U2 - 10.1109/TIT.2012.2200290

DO - 10.1109/TIT.2012.2200290

M3 - Article

VL - 58

SP - 6207

EP - 6222

JO - IEEE Transactions on Information Theory

JF - IEEE Transactions on Information Theory

SN - 0018-9448

IS - 9

M1 - 6203415

ER -