Paper 2019/421 Original: eprint.iacr.org/2019/421 ↗

Continuing to reflect on TLS 1.3 with external PSK

Liliya Akhmetzyanova
Evgeny Alekseev
Ekaterina Smyshlyaeva
Alexandr Sokolov
Abstract

The TLS protocol is the main cryptographic protocol of the Internet. The work on its current version, TLS 1.3, was completed in 2018. This version differs from the previous ones and has been developed taking into account all modern principles of constructing cryptographic protocols. At the same time, even when there are security proofs in some fairly strong security model, it is important to study the possibility of extending this model and then clarifying the security limits of the protocol. In this paper, we consider in detail the restriction on the usage of post-handshake authentication in connections established on external PSK. We clarify that the certain vulnerability appears only in the case of psk_ke mode if more than a single pair of entities can possess a single PSK. We provide several practical scenarios where this condition can be easily achieved. Also we propose appropriate mitigation.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint.
History
2019-04-27: last updated
2019-04-27: published
Short URL
https://ia.cr/2019/421
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2019/421,
      author = {Liliya Akhmetzyanova and Evgeny Alekseev and Ekaterina Smyshlyaeva and Alexandr Sokolov},
      title = {Continuing to reflect on TLS 1.3 with external PSK},
      howpublished = {Cryptology {ePrint} Archive, Paper 2019/421},
      year = {2019},
      url = {https://eprint.iacr.org/2019/421}
}
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