Sure.  s/key size/size/g in my description below.  Sometimes the sizes are for 
things like hash function output size, rather than key size.

From: Manger, James H [mailto:[email protected]]
Sent: Wednesday, August 29, 2012 6:13 PM
To: Mike Jones
Cc: [email protected]
Subject: RE: [jose] (REDO) POLL: RSA-OAEP/RSA-PSS default parameters

There is no 384-bit key involved in RS384 (RSASSA-PKCS1-V1_5 with SHA-384). It 
involves, say, a 2048-bit RSA key.

When you say “key size” do you actually mean “important size”, instead of “size 
of a crypto key”?

Perhaps the hash size and hash algorithm are “more important” in an RSA 
signature than in an RSA encryption padding scheme, though that is a fairly 
subtle hair to be splitting when naming JOSE algorithms. We would need to stop 
talking about “hash algorithms” and start talking about, say, 
“collision-resistant hash algorithms” and “pseudorandom functions” if we want 
to split that hair.

--
James Manger

From: [email protected]<mailto:[email protected]> 
[mailto:[email protected]]<mailto:[mailto:[email protected]]> On Behalf 
Of Mike Jones
Sent: Thursday, 30 August 2012 10:32 AM
To: Manger, James H; Breno de Medeiros
Cc: [email protected]<mailto:[email protected]>
Subject: Re: [jose] (REDO) POLL: RSA-OAEP/RSA-PSS default parameters

They’re in the first category, in which a key size is required to fully specify 
the algorithm.

From: [email protected]<mailto:[email protected]> 
[mailto:[email protected]] On Behalf Of Manger, James H
Sent: Wednesday, August 29, 2012 5:11 PM
To: Mike Jones; Breno de Medeiros
Cc: [email protected]<mailto:[email protected]>
Subject: Re: [jose] (REDO) POLL: RSA-OAEP/RSA-PSS default parameters

So what about RS256, RS384, and RS512?

--
James Manger

From: Mike Jones 
[mailto:[email protected]]<mailto:[mailto:[email protected]]>
Sent: Thursday, 30 August 2012 10:07 AM
To: Breno de Medeiros; Manger, James H
Cc: [email protected]<mailto:[email protected]>
Subject: RE: [jose] (REDO) POLL: RSA-OAEP/RSA-PSS default parameters

Where a key size is required to fully specify the algorithm, it’s included in 
the name.  Examples:  HS256, A128GCM.
Where the size isn’t required to fully specify the algorithm, it isn’t.  
Examples:  RSA1_5, RSA-OAEP, ECSH-ES.

No inconsistency.

                                                            -- Mike

From: [email protected]<mailto:[email protected]> 
[mailto:[email protected]] On Behalf Of Breno de Medeiros
Sent: Wednesday, August 29, 2012 5:01 PM
To: Manger, James H
Cc: [email protected]<mailto:[email protected]>
Subject: Re: [jose] (REDO) POLL: RSA-OAEP/RSA-PSS default parameters

Concur with the analysis that 'RSA-OAEP' terminology appears inconsistent with 
other acronym usage.

On Wed, Aug 29, 2012 at 4:58 PM, Manger, James H 
<[email protected]<mailto:[email protected]>> wrote:
> Should SHA1 (and mgf1SHA1) be the default parameters for these
> algorithms?
We don’t have "algorithm parameters" in JOSE – that is the subject of a 
separate POLL ("Support multiple types for algorithms"). JOSE currently has 
algorithm labels with no parameters.

Consequently this question is really asking one of the following:

Q1. Should RSA OAEP with SHA-1 be defined for use with JOSE? Perhaps 
additionally, should it be mandatory to implement?
The core of this question is whether SHA-1 is cryptographically-compromised 
enough that we shouldn't use it in new crypto specs, or is its 
widespread-availability more important than any crypto weakness?

Q2. Should the label "RSA-OAEP" be used for RSA OAEP with SHA-1?

My answer to Q2 is NO. The "RSA-OAEP" label is inconsistent with other JOSE alg 
names. JWA specifies "HS512", "RS512", "ES512", and "CS512" where the Sxxx 
suffix indicates a hash algorithm. RSA OAEP with SHA-1 could use "ROS1" or 
"ROS160".

--
James Manger

> -----Original Message-----
> From: [email protected]<mailto:[email protected]> 
> [mailto:[email protected]<mailto:[email protected]>] On Behalf Of
> Karen O'Donoghue
> Sent: Thursday, 30 August 2012 7:30 AM
> To: [email protected]<mailto:[email protected]>
> Subject: [jose] (REDO) POLL: RSA-OAEP/RSA-PSS default parameters
>
> Folks,
>
> Given the confusion around the original version of this poll, I'd like
> to try again.
>
> The basic question is unchanged, the room count from Vancouver has been
> corrected, and a clarification regarding the status of SHA1 in the OAEP
> specification has been added.  For those of you who voted and feel you
> may have misunderstood the question or voted incorrectly, please feel
> free to update your answer.
>
> Question:
> Should SHA1 (and mgf1SHA1) be the default parameters for these
> algorithms?
> Note:  These are the default parameters specified in RFC 3447, Section
> A.2.1, and are widely deployed.
>
> Room vote:  5 yes, 0 no, 3 discuss
>
> Thanks,
> Karen
> _______________________________________________
> jose mailing list
> [email protected]<mailto:[email protected]>
> https://www.ietf.org/mailman/listinfo/jose
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--
--Breno
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