## Abstract

The notion of aggregate signature has been motivated by applications and it enables any user to compress different signatures signed by different signers on different messages into a short signature. Sequential aggregate signature, in turn, is a special kind of aggregate signature that only allows a signer to add his signature into an aggregate signature in sequential order. This latter scheme has applications in diversified settings, such as in reducing bandwidth of a certificate chains, and in secure routing protocols. Lu, Ostrovsky, Sahai, Shacham, and Waters presented the first sequential aggregate signature scheme in the standard (non idealized ROM) model. The size of their public key, however, is quite large (i.e., the number of group elements is proportional to the security parameter), and therefore they suggested as an open problem the construction of such a scheme with short keys. Schröder recently proposed a sequential aggregate signature (SAS) with short public keys using the Camenisch-Lysyanskaya signature scheme, but the security is only proven under an interactive assumption (which is considered a relaxed notion of security). In this paper, we propose the first sequential aggregate signature scheme with short public keys (i.e., a constant number of group elements) in prime order (asymmetric) bilinear groups which is secure under static assumptions in the standard model. Technically, we start with a public key signature scheme based on the recent dual system encryption technique of Lewko and Waters. This technique cannot give directly an aggregate signature scheme since, as we observed, additional elements should be published in the public key to support aggregation. Thus, our construction is a careful augmentation technique for the dual system technique to allow it to support a sequential aggregate signature scheme. We further implemented our scheme and conducted a performance study and implementation optimization.

Original language | English |
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Title of host publication | Public-Key Cryptography, PKC 2013 - 16th International Conference on Practice and Theory in Public-Key Cryptography, Proceedings |

Pages | 423-442 |

Number of pages | 20 |

DOIs | |

Publication status | Published - 2013 |

Event | 16th International Conference on Practice and Theory in Public-Key Cryptography, PKC 2013 - Nara, Japan Duration: 2013 Feb 26 → 2013 Mar 1 |

### Publication series

Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
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Volume | 7778 LNCS |

ISSN (Print) | 0302-9743 |

ISSN (Electronic) | 1611-3349 |

### Other

Other | 16th International Conference on Practice and Theory in Public-Key Cryptography, PKC 2013 |
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Country/Territory | Japan |

City | Nara |

Period | 13/2/26 → 13/3/1 |

## ASJC Scopus subject areas

- Theoretical Computer Science
- Computer Science(all)