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I am looking for authenticated key exchange protocols (AKE) based on a generic key encapsulation mechanism (KEM) and providing full/perfect forward secrecy. Optionally, the protocols should offer external anonymity. The idea is to plug into the protocol an existing post-quantum KEM such as CRYSTALS Kyber or SABER.

My research brought me to the following protocols, but which are not totally matching the above-mentioned requirements:

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  • $\begingroup$ You may want to define full/perfect forward secrecy, figure out why (if?) the generic 3-kem construction (your second construction, as used by Kyber) does not achieve it, and then figure out if you care. $\endgroup$
    – K.G.
    Oct 22, 2022 at 15:04
  • $\begingroup$ Not a complete answer, but you may want to look into the IKE protocol framework. It looks like some variants provide PFS. It's stated in terms of DH, but Pei14 shows an IKE-like that works with just CPA-secure KEMs. Please update if you find an answer! $\endgroup$
    – rozbb
    Jul 16, 2023 at 17:26
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    $\begingroup$ The third paper cited claims its construction satisfies foward-security. I agree with K.G. that it should be clarified what property the OP needs that's not satisfied by it. $\endgroup$
    – lamontap
    Mar 13 at 21:26

2 Answers 2

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It is possible to generically add FS to any AKE. BN11 describes a compiler. The caveat is that if you permit ephemeral key revelation in your security model (as is usually permitted in the Canetti-Krawczyk model), then you only get weak FS.

Another route: the $\Sigma_0'$ protocol described in Pei14 is a generic construction that takes an IND-CPA-secure KEM and produces an AKE with strong FS. (there's some extra nuance about its security, explained here, but that's the main idea)

Finally, as others noted, I think the last paper you cited does provide an AKE with strong FS.

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There is one post-quantum AKE with forward secure, which was proposed at EuroCrypt 2015.

This protocol uses noise flooding technique + Ding's RLWE reconciliation-based key exchange to construct a forward-secure post-quantum AKE, as claimed by authors

The security is proven in the Bellare-Rogaway model with weak perfect forward secrecy.

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  • $\begingroup$ These aren't generic over KEMs though $\endgroup$
    – rozbb
    Jul 16, 2023 at 17:39

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