Non-Repudiation in Internet Telephony

  • Nicolai Kuntze
  • Andreas U. Schmidt
  • Christian Hett
Part of the IFIP International Federation for Information Processing book series (IFIPAICT, volume 232)


We present a concept to achieve non-repudiation for natural language conversations over the Internet. The method rests on chained electronic signatures applied to pieces of packet-based, digital, voice communication. It establishes the integrity and authenticity of the bidirectional data stream and its temporal sequence and thus the security context of a conversation. The concept is close to the protocols for Voice over the Internet (VoIP), provides a high level of inherent security, and extends naturally to multilateral non-repudiation, e.g., for conferences. Signatures over conversations can become true declarations of will in analogy to electronically signed, digital documents. This enables binding verbal contracts, in principle between unacquainted speakers, and in particular without witnesses. A reference implementation of a secure VoIP archive is exists.


Packet Loss Session Initiation Protocol Digital Document Signed Document Internet Telephony 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© International Federation for Information Processing 2007

Authors and Affiliations

  • Nicolai Kuntze
    • 1
  • Andreas U. Schmidt
    • 1
  • Christian Hett
    • 2
  1. 1.Fraunhofer-Institute for Secure Information Technology SITDarmstadtGermany
  2. 2.ARTEC Computer GmbHKarbenGermany

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