MergeMAC: A MAC for Authentication with Strict Time Constraints and Limited Bandwidth

Ralph Ankele, Florian Böhl, Simon Friedberger

Research output: Chapter in Book/Report/Conference proceedingConference contribution

44 Downloads (Pure)


This paper presents MergeMAC, a MAC that is particularly suitable for environments with strict time requirements and extremely limited bandwidth. MergeMAC computes the MAC by splitting the message into two parts. We use a pseudorandom function (PRF) to map messages to random bit strings and then merge them with a very efficient keyless function. The advantage of this approach is that the outputs of the PRF can be cached for frequently needed message parts. We demonstrate the merits of MergeMAC for authenticating messages on the CAN bus where bandwidth is extremely limited and caching can be used to recover parts of the message counter instead of transmitting it. We recommend an instantiation of the merging function MERGE and analyze the security of our construction. Requirements for a merging function are formally defined and the resulting EUF-CMA security of MergeMAC is proven.
Original languageEnglish
Title of host publicationACNS 2018 Applied Cryptography & Network security
EditorsBart Preneel, Frederik Vercauteren
Place of PublicationLeuven, Belgium
PublisherSpringer International Publishing
Number of pages19
ISBN (Electronic)978-3-319-93387-0
ISBN (Print)978-3-319-93386-3
Publication statusPublished - 2018

Publication series

NameLecture Notes in Computer Science


  • Symmetric-key cryptography
  • message authentication code
  • lightweight
  • automotive
  • CAN bus

Cite this