Paper 2005/148

On Universal Composable Security of Time-Stamping Protocols

Toshihiko Matsuo and Shin'ichiro Matsuo

Abstract

Time-stamping protocols, which assure that a document was existed at a certain time, are applied to some useful and practical applications such as electronic patent applications and so on. There are two major time-stamping protocols, the simple protocol and the linking protocol. In the former, a time-stamp authority issues a time-stamp token that is the digital signature of the concatenated value of a hashed message and the present time. In the latter, the time-stamp authority issues a time-stamp token that is the hash value of the concatenated value of a hashed message and the previous hash value. Although security requirements and analysis for above time-stamping protocols has been discussed, there are no strict cryptographic security notions for them. In this paper, we reconsider the security requirements for time-stamping protocols and define security notions for them, in a universally composable security sense, which was proposed by Canetti. We also show that these notions can be achieved using combinations of a secure key exchange protocol, a secure symmetric encryption scheme, and a secure digital signature scheme.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Published elsewhere. This paper is accepted as a regular paper at IWAP 2005.
Keywords
time-stamping protocoluniversal composable security
Contact author(s)
matsuosn @ nttdata co jp
History
2005-07-04: revised
2005-05-26: received
See all versions
Short URL
https://ia.cr/2005/148
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2005/148,
      author = {Toshihiko Matsuo and Shin'ichiro Matsuo},
      title = {On Universal Composable Security of Time-Stamping Protocols},
      howpublished = {Cryptology ePrint Archive, Paper 2005/148},
      year = {2005},
      note = {\url{https://eprint.iacr.org/2005/148}},
      url = {https://eprint.iacr.org/2005/148}
}
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