My comments were addressed, however, I wonder if we should finish the base
HPKE specs before taking on new work.

I noticed the algorithm suite names in this draft are still using the
parametric form.

Regards,

OS

On Wed, Jan 15, 2025 at 7:33 AM Michael Prorock <[email protected]> wrote:

> I believe my concerns are addressed
>
> On Tue, Jan 14, 2025, 21:28 Michael Jones <[email protected]>
> wrote:
>
>> Thanks for updating the draft, Tiru.  Ilari, Michael, Michael, Orie, and
>> Sophie, can you please reply-all to this thread saying whether you believe
>> your comments have been addressed or not?
>>
>>
>>
>>                                                                 Thank you,
>>
>>                                                 -- Mike (for the COSE
>> chairs)
>>
>>
>>
>> *From:* tirumal reddy <[email protected]>
>> *Sent:* Thursday, December 12, 2024 5:38 AM
>> *To:* [email protected]; Hannes Tschofenig <
>> [email protected]>
>> *Subject:* Fwd: [COSE] Re: Call for adoption of
>> draft-reddy-cose-jose-pqc-hybrid-hpke
>>
>>
>>
>> Hi Chairs,
>>
>>
>>
>> I have addressed all the comments from the WG for
>> draft-reddy-cose-jose-pqc-hybrid-hpke.
>>
>> Could you consider making a decision on the adoption call now?
>>
>>
>>
>> Cheers,
>>
>> -Tiru
>>
>> ---------- Forwarded message ---------
>> From: *Orie Steele* <[email protected]>
>> Date: Wed, 11 Dec 2024 at 20:35
>> Subject: Re: [COSE] Re: Call for adoption of
>> draft-reddy-cose-jose-pqc-hybrid-hpke
>> To: tirumal reddy <[email protected]>
>> Cc: Sophie Schmieg <[email protected]>, Michael Jones <
>> [email protected]>, [email protected] <[email protected]>
>>
>>
>>
>> Thanks for addressing my comments.
>>
>> I am happy to contribute some data model examples for JWE and COSE
>> Encrypt if I can get some time to code them up.
>>
>> Modulo the ongoing conversation regarding short names for HPKE
>> algorithms, this is looking ready to go from my side.
>>
>> Regards,
>>
>> OS
>>
>>
>>
>> On Wed, Dec 11, 2024 at 12:30 AM tirumal reddy <[email protected]> wrote:
>>
>> Illari, Orie, and Mike P, could you please confirm if your comments have
>> been addressed in the latest version of the draft
>> draft-reddy-cose-jose-pqc-hybrid-hpke
>> <https://datatracker.ietf.org/doc/html/draft-reddy-cose-jose-pqc-hybrid-hpke>
>>  ?
>>
>>
>>
>> -Tiru
>>
>>
>>
>> On Mon, 9 Dec 2024 at 15:53, tirumal reddy <[email protected]> wrote:
>>
>> Hi all,
>>
>> I have published a revised draft (
>> https://www.ietf.org/archive/id/draft-reddy-cose-jose-pqc-hybrid-hpke-05.html),
>> which addresses all comments raised, particularly from Orie and Ilari.  The
>> draft appears ready for adoption.
>>
>> Cheers,
>> -Tiru
>>
>> On Fri, 6 Dec 2024 at 15:36, tirumal reddy <[email protected]> wrote:
>>
>> Hi Orie,
>>
>>
>>
>> I raised a PR https://github.com/tireddy2/Hybrid-KEM-with-COSE-JOSE/pulls
>> to use "AKP".
>>
>>
>>
>> Cheers,
>>
>> -Tiru
>>
>>
>>
>> On Thu, 5 Dec 2024 at 04:05, Orie Steele <[email protected]>
>> wrote:
>>
>> Changing "crv" is indeed not possible at this point.... but we are not
>> required to use "crv" to express pqc or hybrid keys.
>>
>> The document that enables an "alg" to be used in a message can also
>> specify which "kty" and other parameters are required to be present when
>> that alg is expressed in a key.
>>
>> We are comparing:
>>
>> ### Option A
>>
>> const jwk = {
>>     kty: "AKP", // mandatory
>>     alg: "X-Wing", // mandatory
>>     pub: "4iNrNajCSz...tmrrIzQSQQO9lNA", // mandatory
>>     priv: "f5wrpOiP...rPpm7yY", // mandatory
>> };
>>
>> ### Option B
>>
>> const jwk = {
>>     kty: "OKP", // mandatory
>>     crv: "X-Wing", // mandatory
>>     alg: "X-Wing", // optional
>>     x: "4iNrNajCSz...tmrrIzQSQQO9lNA", // mandatory
>>     d: "f5wrpOiP...rPpm7yY" // mandatory
>> };
>>
>> I'm saying let's go with Option A.
>>
>>
>>
>> On Wed, Dec 4, 2024 at 4:22 PM Sophie Schmieg <[email protected]>
>> wrote:
>>
>> I would really like to avoid a reality where someone uses the separate
>> parts of an X-Wing key in their own primitives, that way lies madness and
>> vulnerabilities. COSE should treat hybrids just like any other algorithm,
>> and pretend to not know anything about how the opaque blob of bytes
>> operates.
>>
>> As for unfortunate naming decisions, there is some precedent here, with
>> TLS calling everything a group. Kind of unfortunate and "algorithm
>> parameter" or similar would have been the far better term for it, but I
>> somewhat assume that changing this name at this point is infeasible. (An
>> overly pendadic person might point out though, that Z[X]/(X^256+1)^3 is, as
>> a module of a number field order, by definition still a group, and that
>> Z[X](X^256+1) has Dedekind dimension one, which means that it would be fair
>> to say that at least Spec Z[X]/(X^256+1) is a curve, so we are still
>> talking about a vector bundle over a curve)
>>
>>
>>
>> On Wed, Dec 4, 2024 at 6:25 AM tirumal reddy <[email protected]> wrote:
>>
>> Thanks Orie for valuable inputs, raise PRs for both the drafts, see
>> https://github.com/tireddy2/Hybrid-KEM-with-COSE-JOSE/pull/4
>> and https://github.com/ietf-wg-jose/draft-ietf-jose-hpke-encrypt/pull/11
>> .
>>
>>
>>
>> On Tue, 3 Dec 2024 at 20:08, Orie Steele <[email protected]>
>> wrote:
>>
>> Sure, but that is a problem for:
>>
>> https://datatracker.ietf.org/doc/draft-ietf-cose-hpke/
>> https://datatracker.ietf.org/doc/draft-ietf-jose-hpke-encrypt/
>>
>> Consider what the example you gave above means in a pre-hpke world:
>>
>> {
>>       "kty": "OKP",
>>       "crv": "X25519",
>>       "algorithms": ["ECDH-ES+A128KW", "ECDH-ES+A256KW"],
>>       "x": "KIWi1p4buN7...N8zkhfF8pGs",
>> }
>>
>> The algorithms in the key are for key establishment / key wrapping... not
>> content encryption.
>>
>> HPKE is adding the idea of enabling "direct integrated encryption".
>> ... and in doing so, enabling you to use a key wrapping algorithm which
>> is also a content encryption algorithm and which is an hpke aead.
>> If that's a bad idea, we are not making it better by adding PQ/T hybrids
>> to it, or enabling multiple HPKE suites to be used for the same KEM key.
>>
>> https://datatracker.ietf.org/doc/html/rfc9180#name-kem-key-reuse
>>
>> So while HPKE might allow the same kem key to be used with multiple
>> AEADs, there is no reason that JOSE and COSE should allow it...
>> *Because this use case is solved for in the 2 layer constructions in JOSE
>> and COSE.*
>>
>> I consider it to be a bad idea to advertise multiple key encryption / key
>> wrapping algorithms for a single kem key pair.
>>
>> Let's look at a complete example of X-Wing in JOSE starting with the
>> recipient public key:
>>
>> {
>>     "kty": "AKP",
>>     "kid":
>> "urn:ietf:params:oauth:jwk-thumbprint:sha-256:S6AXfdU_6Yfzvu0KDDJb0sFuwnIWPk6LMTErYhPb32s",
>>     "alg": "HPKE-XWING-SHA256-A256GCM",
>>     "pub": "KIWi1p4buN7...N8zkhfF8pGs",
>>     "priv": "i20zlCBQr0...JsShVkf3q4qUc"
>> }
>>
>> ^ such a key can be used for both integrated encryption and 2 key
>> encryption in both JOSE and COSE.
>>
>> You can encrypt directly to this key using A256GCM,
>> and indirectly by using HPKE-XWING-SHA256-A256GCM to encrypt a content
>> encryption key, and then using any of the algorithms registered here:
>>
>>
>> https://www.iana.org/assignments/jose/jose.xhtml#web-signature-encryption-algorithms
>> ... that support "enc" ... (ChaCha20Poly1305 is not in this registry btw).
>>
>> ## Integrated Encryption (X-Wing HPKE JWT)
>>
>> {
>>   "protectedHeader": {
>>     "alg": "HPKE-XWING-SHA256-A256GCM",
>>     "enc": "dir",
>>     "kid":
>> "urn:ietf:params:oauth:jwk-thumbprint:sha-256:S6AXfdU_6Yfzvu0KDDJb0sFuwnIWPk6LMTErYhPb32s"
>>   },
>>   "payload": {
>>     "urn:example:claim": true,
>>     "iss": "urn:example:issuer",
>>     "aud": "urn:example:audience",
>>     "iat": 1729785491,
>>     "exp": 1729792691
>>   }
>> }
>>
>> ## Key Encryption (Multiple recipients, using the same content
>> encryption algorithm)
>>
>> {
>>   "protected": "eyJlbmMiOiJBMTI4R0NNIn0", // { "enc" : "A128GCM" }
>>   "iv": "ZL0HDvZJizA6vyTV",
>>   "ciphertext": "Oq26x9vppULrGNzCn2j...BgQpgJPchg0eWNmgv4Ozi5I",
>>   "tag": "ULnlOiJRYfCzM_r5j9sLEQ",
>>   "aad": "cGF1bCBhdHJlaWRlcw",
>>   "recipients": [
>>     {
>>       "encrypted_key": "G3HmlpOgA4H...w7svDwUqvNR",
>>       "header": {
>>         "kid": "urn:ietf:params:oauth:jwk-thumbprint:sha-256:
>> cxQC_lWt22BIjH5AWSLHCZk_f-mU3-W4Ztcu5-ZbwTk",
>>         "alg": "ECDH-ES+A128KW",
>>         "epk": {
>>           "kty": "OKP",
>>           "crv": "X25519",
>>           "x": "JnGWSQ90hlt0H7..._Dn_CkLzE",
>>         }
>>       }
>>     },
>>     {
>>       "encrypted_key": "pn6ED0ijngCiWF8...mRF7QarTVfuWj6dw",
>>       "header": {
>>         "alg": "HPKE-XWING-SHA256-A256GCM",
>>         "kid":
>> "urn:ietf:params:oauth:jwk-thumbprint:sha-256:S6AXfdU_6Yfzvu0KDDJb0sFuwnIWPk6LMTErYhPb32s",
>>         "ek": "BI41YDnhTTI6jSd7T62rLwzC...X9UXDw_3ylbXTiYWmPXl2fNmr4BeQ"
>>       }
>>     }
>>   ]
>> }
>>
>> Some comments on kem key reuse:
>>
>> In the example above, assume the X25519 ECDH-ES+A128KW part is to the
>> x25519 component of the X-Wing key.
>> When a CRQC breaks ECDH-ES, the encrypted content encryption key is
>> broken, and the attacker can ignore x-wing completely, and still recover
>> the plaintext.
>> This remains true when any recipient in a 2 layer uses any of the
>> traditional 2 layer algorithms in the JOSE and COSE registries today
>> (except for psk stuff mixed into kdfs).
>>
>> In the case of direct encryption to the x25519 component of an x-wing
>> key, the plaintext is also recovered.
>>
>> The only way to protect against both modes is to use X-Wing for both
>> integrated encryption and key encryption and to always use the full x-wing
>> algorithm with a given x-wing key, and in the case of multiple recipients,
>> to ensure that each recipient is using a PQ key encryption / key wrapping
>> algorithm.... because in 2 layer breaking a single recipient encrypted
>> content encryption key recovers plaintext.
>>
>> OS
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> On Tue, Dec 3, 2024 at 6:57 AM tirumal reddy <[email protected]> wrote:
>>
>> Thanks Orie for the detailed explanation. I understand your suggestion to
>> use "AKP" instead of "OKP," but "AKP" has limitations, particularly with
>> the HPKE PQ/T scheme. For example, in the HPKE, a single key agreement
>> mechanism can be paired with multiple AEAD algorithms, resulting in unique
>> cryptographic algorithm identifiers. For instance:
>>
>>    - HPKE-XWING-SHA256-ChaCha20Poly1305
>>    - HPKE-XWING-SHA256-AES256GCM
>>
>> To address this, the key type "AKP" would need to be extended to
>> accommodate multiple algorithms. A possible JSON representation could look
>> like this:
>>
>> {
>>
>>     "kty": "AKP",
>>
>>     "kid": "01",
>>
>>     "algorithms": [
>>
>>         "HPKE-XWING-SHA256-ChaCha20Poly1305",
>>
>>         "HPKE-XWING-SHA256-AES256GCM"
>>
>>     ],
>>
>>     "key_ops": [
>>
>>         "deriveBits",
>>
>>         "wrapKey"
>>
>>     ]
>>
>> }
>>
>>
>>
>> -Tiru
>>
>>
>>
>> On Tue, 3 Dec 2024 at 02:25, Orie Steele <[email protected]>
>> wrote:
>>
>>
>> https://author-tools.ietf.org/iddiff?url1=draft-reddy-cose-jose-pqc-hybrid-hpke-03&url2=draft-reddy-cose-jose-pqc-hybrid-hpke-04&difftype=--hwdiff
>>
>> Further comments:
>>
>> X-Wing is not an Elliptic Curve.
>>
>> X-Wing keys using OKP and (ab)using the "crv" parameter to mean "curve
>> with parameters + lattice with parameters"... is something I really hope we
>> can decide not to do.
>>
>> As I said in
>> https://mailarchive.ietf.org/arch/msg/cose/LMh6LpT5aqF5m47dmQ_roWU18eM/
>>
>> It would be nice to agree to use keys for algorithms, and to use AKP for
>> ML-KEM and ML-DSA, and X-Wing with HPKE, and X-Wing without HPKE... and all
>> of this is possible with the use of the AKP key type with fully specified
>> algorithms.
>>
>>
>> https://datatracker.ietf.org/doc/html/draft-ietf-cose-dilithium-04#name-algorithm-key-pair-type
>>
>> Obviously I disagree with Ilari on this point.
>> .... however, I hope we can agree that whatever we do for ML-DSA, it will
>> work for ML-KEM and X-Wing, and HPKE... or whatever CRFG comes up with next.
>>
>> *In summary, it's nice that the HPKE algorithms have been added, but I
>> object to the key representation using OKP.*
>>
>> Motivation for my objection to the use of OKP for ML-KEM keys:
>>
>> Consider that OKP is commonly considered reserved for "elliptic curve
>> points", as noted in
>> https://datatracker.ietf.org/doc/html/rfc8152#section-12.4.2
>>
>> https://www.rfc-editor.org/rfc/rfc8037.html#section-2
>>
>>    Note: Do not assume that there is an underlying elliptic curve,
>>    despite the existence of the "crv" and "x" parameters.  (For
>>    instance, this key type could be extended to represent Diffie-Hellman
>>    (DH) algorithms based on hyperelliptic surfaces.)
>>
>> It does not matter how many times I read the note above, the normative
>> MUST says:
>>
>>   o  The parameter "crv" MUST be present and contain the subtype of the
>>       key (from the "JSON Web Elliptic Curve" registry).
>>
>>
>> This means we are required to put things that are not curves in a
>> registry for curves....
>>
>> If the algorithm param "alg" is not mandatory for an X-Wing key, can I
>> use the same key for ML-KEM and X25519 and X-Wing?
>>
>> Do I have to put "alg" in the key, even though it's optional (in OKP) to
>> signal a safer use pattern?
>> If I encrypt with X25519 to an X-Wing key that has no "alg" parameter,
>> what happens?... is it ok, if I use the X25519 component to decrypt? it
>> works... is this legal?
>>
>> {
>>       "kty": "OKP",
>>       "crv": "X-Wing", // not a curve... just means x and d cannot be
>> validated... unless you know the intended algorithm
>>       "alg": "ECDH-ES+A128KW", // HPKE-XWING-SHA256-AES256GCM
>> // HPKE-X25519-SHA256-CHACHA20POLY1305
>>       "x": "KIWi1p4buN7...N8zkhfF8pGs", // 2 public keys
>>       "d": "i20zlCBQr0...JsShVkf3q4qUc" // 2 private keys or a single
>> seed for both private keys
>> }
>>
>> The thumbprints will be different ...
>> https://datatracker.ietf.org/doc/html/draft-ietf-cose-key-thumbprint-06#name-octet-key-pair-okp
>>
>> Even if the same private key can decrypt messages to each public key that
>> contains "somewhere (no validation)" the necessary components....
>>
>> The thumbprint for a hybrid public key should include the algorithm used
>> to construct the hybrid, not just the public keys used with any component
>> algorithms or the hybrid.
>>
>> Either we should scrap the AKP concept and use OKP as Ilari suggested.
>> ... or we should not use OKP for new "subtype"s... and especially not for
>> hybrids.
>>
>> I don't know if this comment should gate working group adoption, but it
>> certainly seems it should gate a WGLC for either document that references
>> ML-KEM / ML-DSA .
>> Thanks to Russ, Neil and others who gave WGLC feedback on AKP and ML-DSA
>> for JOSE and COSE, I am tracking your comments here:
>> https://github.com/cose-wg/draft-ietf-cose-dilithium/issues but have not
>> yet addressed them.
>>
>> Ilari, Hannes and Tiru, please feel free to file a WGLC comment on the
>> use of AKP in ML-DSA.
>>
>> Whatever the outcome, there should be alignment on seeds, private keys,
>> public keys and algorithms for lattice and hybrid PQC (ML-DSA / ML-KEM /
>> X-Wing)
>>
>> "pub" is better than "x"
>>
>> "priv" is better than "d"
>>
>> "alg" should have been mandatory in keys,
>> ... and forbidden in headers ( a ship that has sailed, and can't be fixed
>> for EC2 / OKP keys, or JWE / COSE Encrypt envelopes )...
>>
>> *...things that are not elliptic curves do not belong in a registry for
>> elliptic curves...*
>>
>>
>> I will die on these hills. If I'm in the rough, it would be good to know.
>>
>> OS
>>
>>
>>
>>
>>
>> On Mon, Dec 2, 2024 at 11:11 AM Michael Jones <
>> [email protected]> wrote:
>>
>> Ilari, Orie, and Mike P., do you believe that your comments on the
>> previous draft have been addressed in this one?  If not, what further
>> changes would you suggest?
>>
>>
>>
>>                                                                 Thanks
>> all,
>>
>>                                                                 -- Mike
>>
>>
>>
>> *From:* tirumal reddy <[email protected]>
>> *Sent:* Monday, December 2, 2024 5:29 AM
>> *To:* Michael Jones <[email protected]>
>> *Cc:* [email protected]
>> *Subject:* Re: [COSE] Re: Call for adoption of
>> draft-reddy-cose-jose-pqc-hybrid-hpke
>>
>>
>>
>> The revised draft
>> https://www.ietf.org/archive/id/draft-reddy-cose-jose-pqc-hybrid-hpke-04.html
>> addresses all the comments raised during the WG adoption call. Regarding
>> Michael's comment on the terms 'traditional' and 'Post-Quantum,' this issue
>> has been discussed in the PQUIP WG. However, no decision has been made to
>> change the terminology, and this issue is beyond the scope of this
>> document
>>
>>
>>
>> -Tiru
>>
>>
>>
>> On Sat, 30 Nov 2024 at 22:42, Michael Jones <[email protected]>
>> wrote:
>>
>> Only two replies to the call for adoption clearly stated that they
>> favored adoption.  Whereas more messages were sent than that with critiques
>> of the draft.  Therefore, the draft is not adopted in its present form.
>>
>>
>>
>> The chairs suggest that the authors update the specification to address
>> the feedback from Ilari, Orie, Mike P., and Michael R. and publish a new
>> draft, and then ask for feedback on the revised draft on the mailing list.
>> Following that, we can consider a call for adoption of the revised draft.
>>
>>
>>
>>                                                                 For the
>> chairs,
>>
>>                                                                 -- Mike
>>
>>
>>
>> *From:* Michael Jones
>> *Sent:* Friday, November 8, 2024 7:04 AM
>> *To:* [email protected]
>> *Subject:* Call for adoption of draft-reddy-cose-jose-pqc-hybrid-hpke
>>
>>
>>
>> Per discussions at the IETF 121 COSE working group meeting, this note
>> starts a two-week call for adoption of the PQ/T Hybrid KEM: HPKE with
>> JOSE/COSE specification.  Please let us know whether you are in favor of
>> adoption or not by Friday, November 22, 2024.
>>
>>
>>
>>                                                                 Thank you,
>>
>>                                                                 -- Mike &
>> Ivo
>>
>>
>>
>> _______________________________________________
>> COSE mailing list -- [email protected]
>> To unsubscribe send an email to [email protected]
>>
>> _______________________________________________
>> COSE mailing list -- [email protected]
>> To unsubscribe send an email to [email protected]
>>
>>
>>
>>
>> --
>>
>>
>>
>>
>> *ORIE STEELE *Chief Technology Officer
>> www.transmute.industries
>>
>> <https://transmute.industries/>
>>
>>
>>
>>
>> --
>>
>>
>>
>>
>> *ORIE STEELE *Chief Technology Officer
>> www.transmute.industries
>>
>> <https://transmute.industries/>
>>
>> _______________________________________________
>> COSE mailing list -- [email protected]
>> To unsubscribe send an email to [email protected]
>>
>>
>>
>>
>> --
>>
>>
>> Sophie Schmieg | Information Security Engineer | ISE Crypto |
>> [email protected]
>>
>>
>>
>>
>>
>>
>> --
>>
>>
>>
>>
>> *ORIE STEELE *Chief Technology Officer
>> www.transmute.industries
>>
>> <https://transmute.industries/>
>>
>>
>>
>>
>> --
>>
>>
>>
>>
>> *ORIE STEELE *Chief Technology Officer
>> www.transmute.industries
>>
>> <https://transmute.industries/>
>>
>

-- 


ORIE STEELE
Chief Technology Officer
www.transmute.industries

<https://transmute.industries>
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