Re: [CFRG] I-D Action: draft-irtf-cfrg-hpke-10.txt

[Dan Harkins <[e-mail]>]

   Hello,

   -10 includes a new section, 9.4, that says:

      "All AEADs MUST be IND-CCA2-secure, as is currently true for all AEADs
       listed in Section 7.3"

I don't believe this was discussed on the list and I don't agree with it.
Using the AEADs in section 7.3 will give you a construction that is IND-CCA2
secure but I don't think that all uses of HPKE MUST be.

   I have a draft on adding support for deterministic authenticated 
encryption
to HPKE and this subtle addition to -10 closes the door on that. Since 
we did
not discuss this addition I'd like to start discussing it before this draft
gets too far.

   regards,

   Dan.

On 7/7/21 8:54 AM, [e-mail] wrote:
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> This draft is a work item of the Crypto Forum RG of the IRTF.
>
>          Title           : Hybrid Public Key Encryption
>          Authors         : Richard L. Barnes
>                            Karthik Bhargavan
>                            Benjamin Lipp
>                            Christopher A. Wood
> 	Filename        : draft-irtf-cfrg-hpke-10.txt
> 	Pages           : 104
> 	Date            : 2021-07-07
>
> Abstract:
>     This document describes a scheme for hybrid public-key encryption
>     (HPKE).  This scheme provides a variant of public-key encryption of
>     arbitrary-sized plaintexts for a recipient public key.  It also
>     includes three authenticated variants, including one which
>     authenticates possession of a pre-shared key, and two optional ones
>     which authenticate possession of a KEM private key.  HPKE works for
>     any combination of an asymmetric key encapsulation mechanism (KEM),
>     key derivation function (KDF), and authenticated encryption with
>     additional data (AEAD) encryption function.  Some authenticated
>     variants may not be supported by all KEMs.  We provide instantiations
>     of the scheme using widely used and efficient primitives, such as
>     Elliptic Curve Diffie-Hellman key agreement, HKDF, and SHA2.
>
>     This document is a product of the Crypto Forum Research Group (CFRG)
>     in the IRTF.
>
>
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-irtf-cfrg-hpke/
>
> There is also an HTML version available at:
> https://www.ietf.org/archive/id/draft-irtf-cfrg-hpke-10.html
>
> A diff from the previous version is available at:
> https://www.ietf.org/rfcdiff?url2=draft-irtf-cfrg-hpke-10
>
>
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
>
>
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