I raised a new PR https://github.com/tireddy2/PQC_JOSE_COSE/pull/20 to
address the issue.

Cheers,
-Tiru

On Wed, 22 Oct 2025 at 21:37, Orie <[email protected]> wrote:

> If we assume AKP, and there is a desire to restrict a key to only
> integrated encryption, then the algorithm identifiers would need to be
> updated.
>
> I can buy the security argument that it should be possible to restrict a
> key to only integrated encryption... Especially because with key encryption
> a weaker recipient could be attacked leading to disclosure.
>
> Having a way to distinguish the supported  algorithms also fits with the
> spirit of fully specified algorithms.
>
> Regards,
>
> OS
>
> On Wed, Oct 22, 2025, 1:09 AM tirumal reddy <[email protected]> wrote:
>
>> I am good to proceed with defining a new key type for PQC KEMs and to
>> keep the "alg" parameter optional. Implementations that require strict
>> algorithm binding can mandate the presence of "alg".  The "alg" field can
>> be omitted when the same key structure is reused across different modes,
>> such as direct encryption and key wrap similar to the way "alg" is not
>> specified for the existing OKP key type.
>>
>> Cheers,
>> -Tiru
>>
>> On Wed, 22 Oct 2025 at 03:04, Brian Campbell <bcampbell=
>> [email protected]> wrote:
>>
>>> Apologies, the beginning of the text in the parenthetical of that last
>>> sentence should have said "I'm *not* totally convinced myself"
>>>
>>> On Tue, Oct 21, 2025 at 1:34 PM Brian Campbell <
>>> [email protected]> wrote:
>>>
>>>> Agree with much of Orie's perspective here.
>>>>
>>>> Please do not attempt to redefine AKP.
>>>>
>>>> If consensus is that AKP isn't right for keys for PQ KEMs (I'm
>>>> totally convinced myself but I do definitely understand some of the
>>>> rationale), then new key type(s) are the appropriate way forward.
>>>>
>>>> On Sat, Oct 11, 2025 at 7:32 AM Orie <[email protected]> wrote:
>>>>
>>>>> I left comments on https://github.com/tireddy2/PQC_JOSE_COSE/pull/19
>>>>>
>>>>> I will repeat them here for the list.
>>>>>
>>>>> Do not update the definition of AKP.
>>>>>
>>>>> Make a new key type if you want to have keys that have a different set
>>>>> of security properties (such as being explicitly used with multiple
>>>>> algorithms).
>>>>>
>>>>> If you want to go this route, I would lean into the idea that you
>>>>> can't actually enforce any algorithm checking at the key side, and just 
>>>>> say
>>>>> that the attacker controlling the algorithm in the message is not a 
>>>>> concern
>>>>> for kems.
>>>>> (I don't agree with this, but that's what the argument appears to be
>>>>> to me, please correct me if I am wrong).
>>>>>
>>>>> In JOSE and COSE, the algorithm on security objects is controlled by
>>>>> the attacker.
>>>>> Without requiring the algorithm to be on the key, you will need to
>>>>> "try it out" to see if it works.
>>>>> As soon as you do that, you are doing work for the attacker... The
>>>>> system may still fail closed, but you've already done more work than you
>>>>> needed to.
>>>>>
>>>>> It's easy to make a new key type, if the WG thinks a key type that can
>>>>> explicitly be used with many algorithms is a good thing, make one, that 
>>>>> way
>>>>> people will know what they are getting when they see that key type.
>>>>>
>>>>> Regards,
>>>>>
>>>>> OS
>>>>>
>>>>>
>>>>>
>>>>> On Sat, Oct 11, 2025 at 8:09 AM Neil Madden <[email protected]>
>>>>> wrote:
>>>>>
>>>>>>
>>>>>>
>>>>>> > On 11 Oct 2025, at 13:24, Ilari Liusvaara <[email protected]>
>>>>>> wrote:
>>>>>> >
>>>>>> > On Sat, Oct 11, 2025 at 10:29:59AM +0100, Neil Madden wrote:
>>>>>> >>
>>>>>> https://neilmadden.blog/2018/09/30/key-driven-cryptographic-agility/
>>>>>> >
>>>>>> > AKP is incompatible with key driven cryptographic agility.
>>>>>> >
>>>>>> > The idea of key driven cryptographic agility is to specify some
>>>>>> > cryptographic service (e.g., signature, mac, KEM) at protocol level
>>>>>> and
>>>>>> > then have key specify how exactly that is implemented. And since
>>>>>> this
>>>>>> > is polymorphic by definition, KDCA is also incompatible with fully
>>>>>> > specified algorithms.
>>>>>>
>>>>>> None of these things is true.
>>>>>>
>>>>>> — Neil
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