Paper 2018/342 Original: eprint.iacr.org/2018/342 ↗

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

Ralph Ankele
Florian Böhl
Simon Friedberger
Abstract

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.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint.
History
2018-04-16: last updated
2018-04-16: published
Short URL
https://ia.cr/2018/342
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2018/342,
      author = {Ralph Ankele and Florian Böhl and Simon Friedberger},
      title = {MergeMAC: A MAC for Authentication with Strict Time Constraints and Limited Bandwidth},
      howpublished = {Cryptology {ePrint} Archive, Paper 2018/342},
      year = {2018},
      url = {https://eprint.iacr.org/2018/342}
}
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