Encoding in the DTMF Channel for Two-Channel Authentication

  • Alessio MeneghettiEmail author
  • Pietro Peterlongo
  • Massimiliano Sala
Conference paper
Part of the Lecture Notes in Electrical Engineering book series (LNEE, volume 358)


A typical situation of authentication happens when an Internet service needs to verify the identity of a user. The channel used for the communication could be under attack and it is envisaged that a second channel should be employed to thwart this threat. A type of channel which is widely available and that might be suitable for this goal is the DTMF signaling. Telephone lines use Dual-Tone Multi-Frequency signaling (DTMF) to communicate between devices such as a telephone and a server. DTMF uses a sixteen symbols code. The channel presents noise which may produce missing or doubled symbols. Given the extremely limited bandwidth, it is essential to provide some encoding that can protect the exchanged secret from the channel noise. This problem requires the use of Insertion Deletion Codes. In this contribution we describe the problem and our solution, which employs a concatenation of Reed-Solomon codes and Tenengolts codes, that solves it in our particular context, i.e. reduced bandwith with the goal of exchanging a secret for a two-channel authentication protocol.



The first author would like to thank his PHD supervisor: the third author.


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Alessio Meneghetti
    • 1
    Email author
  • Pietro Peterlongo
    • 1
  • Massimiliano Sala
    • 1
  1. 1.University of TrentoTrentoItaly

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