- From: David Chadwick <D.W.Chadwick@kent.ac.uk>
- Date: Tue, 22 Dec 2020 11:17:03 +0000
- To: public-credentials@w3.org
If hashes become reversible I think we are all dead in the water as all cryptography depends on the non-reversible property. Furthermore, reducing an infinite data pool into a finite number of hashes means there are bound to be collisions, so reversibility can never be 100% guaranteed. (in fact there are theoretically an infinite number of data items that will create the same hashed value). Kind regards David On 22/12/2020 10:19, Joosten, H.J.M. (Rieks) wrote: > > I am not sure, but I think the argument is that what is not > reversible/brute forceable today, may not have that property tomorrow. > > And if that were to happen, you have no clue how far reaching the > consequences are going to be. > > The uncertainty of such consequences (i.e. the risk) is therefore very > high. > > Rieks > > *From:*Steve Capell <steve.capell@gmail.com> > *Sent:* dinsdag 22 december 2020 11:02 > *To:* Marnix.van.den.Bent@rabobank.nl > *Cc:* williamc@itr8.com; arshad.noor@strongkey.com; > public-credentials@w3.org > *Subject:* Re: OpenAttestation (was Re: looking for a specific use-case) > > A salted hash is considered private data ? Really? It’s not reversible > and, thanks to salt, not brute force guesssble > > Is there a cryptographic miracle that permits actual private data to > be reversed out of a salted hash? Or is this a case of otherwise very > sensible legislation gone a bit off the rails ? > > Steven Capell > > Mob: 0410 437854 > > > > On 22 Dec 2020, at 8:39 pm, Marnix.van.den.Bent@rabobank.nl > <mailto:Marnix.van.den.Bent@rabobank.nl> wrote: > > > > We used to collab with GovTech and Accredify for a short time to > explore OpenCerts about a year ago. It’s a cool solution dedicated > to easily verify certificates and also render them using the > template of the issuing party. At that time they did have a > centralized registry (https://docs.opencerts.io/docs/registry > <https://docs.opencerts.io/docs/registry>) but also the > possibility to verify using DNS. We did see that there was no > mechanism in place to verify the presenter (like we have signature > proofs bound to CredentialSubject id), since they assume you’d > identify yourself on the actual job interview for example. Also we > found some GDPR complications; The OpenCerts can be issued in > batches, results into one student having an OpenCert file > containing hashes of other OpenCerts. Whilst it is very unlikely > to reverse engineer the hash due to the salts, our government > still treats it as personal data, even if it’s hashed. And we > don’t have legal grounds to process those.. > > Kind regards, > > Marnix van den Bent > > +31 88 72 19312 > > *Van: *Steve Capell <steve.capell@gmail.com > <mailto:steve.capell@gmail.com>> > *Datum: *maandag 21 december 2020 om 16:21 > *Aan: *Bill Claxton <williamc@itr8.com <mailto:williamc@itr8.com>> > *CC: *Arshad Noor <arshad.noor@strongkey.com > <mailto:arshad.noor@strongkey.com>>, "W3C Credentials CG (Public > List)" <public-credentials@w3.org <mailto:public-credentials@w3.org>> > *Onderwerp: *Re: OpenAttestation (was Re: looking for a specific > use-case) > *Opnieuw verzenden - Van: *<public-credentials@w3.org > <mailto:public-credentials@w3.org>> > *Opnieuw verzenden - Datum: *maandag 21 december 2020 om 16:19 > > Interesting article bill > > May well be correct for the use case you describe of Singapore’s > education system. But I think it needs to be updated to reflect > current state for our cross border use: > > - you talk about a central register of approved issuers, but there > is no managed register of issuer identities. The issuer ID is > linked to their DNS. abf.gov.au for example, which obviously > needed no approval from Singapore > > - you say that the certificate is stored in free text, but > actually it is symmetrically encrypted using a one time password > > One interesting question is how the subject (not the issuer) is > identified. Not a DID. Actually just a public domain identifier > like a business registration number. I guess this is one of the > core differences between open attestation and VCs. I think this > goes to the use case for tyres things in international trade. > Unlike a VC style bearer token where the presenter is almost > always the subject, these are rather more transactional > credentials (eg a certificate of origin about a consignment of > goods from an exporter) where the presenter is often (usually) not > the subject. Eg a certificate of origin pathway is issuer > (chamber) -> subject (exporter) -> freight forwarder -> importer > -> customs broker -> verifier (importing customs agent). I don’t > know (but willing to learn) how you’d practically make this work > if each party in the chain needed to verify DIDs > > Cheers > > Steven Capell > > Mob: 0410 437854 > > > > > On 21 Dec 2020, at 11:26 pm, Bill Claxton <williamc@itr8.com > <mailto:williamc@itr8.com>> wrote: > > Arshad, > > OpenAttestation was an underlying component of OpenCerts. You > may find this paper > <https://github.com/WebOfTrustInfo/rwot9-prague/blob/master/topics-and-advance-readings/Decentralising%20OpenCerts%20v2.md> > that I co-wrote provides some history and establishes the > rationale for creating it, and why we felt that many > governments would do the same thing. A lot of the > recommendations in that paper have since been implemented and, > as Steve said, there are plans to better align with the VC > data model and use of DIDs. > > The main page for OpenCerts <http://opencerts.io/> uses an .io > top level domain. Not sure about the choice of .com over .org > for OpenAttestations. > > Regards, Bill Claxton (williamc@itr8.com > <mailto:williamc@itr8.com>) > Facebook, Skype, MSN, Yahoo, Twitter, Flickr or Gmail: wmclaxton > Voice, Text or Whatsapp: +65-9012-4327 > > On 12/21/2020 9:45 AM, Arshad Noor wrote: > > I'm not sure I understand Steve. > > The home page says "OpenAttestation is an open-sourced > framework to notarise documents using the blockchain." > But, I don't see any white-paper anywhere on: > > - The business problem it solves; or > - Why existing schemes/technology do not solve the problem > that necessitates the use of a new framework. > > Does such a white-paper exist? > > Thanks. > > Arshad > > P.S. Curious that an "open" framework would choose to > publish its content on a commercial .com domain rather > than the traditional top level domain for open-source > projects: .org. > > > On 12/19/20 1:59 PM, Steve Capell wrote: > > > https://www.openattestation.com/ > <https://www.openattestation.com/> > <https://www.openattestation.com/> > <https://www.openattestation.com/> > > Used by > > https://www.tradetrust.io/ > <https://www.tradetrust.io/> > <https://www.tradetrust.io/> > <https://www.tradetrust.io/> (A Singapore government > site) > > And by > > https://igl.trade.np.cp1.abf.gov.au/ > <https://igl.trade.np.cp1.abf.gov.au/> > <https://igl.trade.np.cp1.abf.gov.au/> > <https://igl.trade.np.cp1.abf.gov.au/> (Au government > - beta trial only) > > Part of a UN collaboration described here > https://uncefact.unece.org/pages/viewpage.action?mobileBypass=true&spaceKey=uncefactpublic&title=Cross+border+Inter-ledger+exchange+for+Preferential+CoO+using+Blockchain > <https://uncefact.unece.org/pages/viewpage.action?mobileBypass=true&spaceKey=uncefactpublic&title=Cross+border+Inter-ledger+exchange+for+Preferential+CoO+using+Blockchain> > <https://uncefact.unece.org/pages/viewpage.action?mobileBypass=true&spaceKey=uncefactpublic&title=Cross+border+Inter-ledger+exchange+for+Preferential+CoO+using+Blockchain> > <https://uncefact.unece.org/pages/viewpage.action?mobileBypass=true&spaceKey=uncefactpublic&title=Cross+border+Inter-ledger+exchange+for+Preferential+CoO+using+Blockchain> > > > > > Steven Capell > Mob: 0410 437854 > > > > On 19 Dec 2020, at 11:51 pm, Arshad Noor > <arshad.noor@strongkey.com> > <mailto:arshad.noor@strongkey.com> wrote: > > What is this protocol, Steve? A search does not > identify the protocol uniquely: > https://duckduckgo.com/?t=ffab&q=singapore+open+attestation+protocol&ia=web > <https://duckduckgo.com/?t=ffab&q=singapore+open+attestation+protocol&ia=web> > > Thanks. > > Arshad Noor > StrongKey > > On 12/19/20 4:25 AM, Steve Capell wrote: > > > In our international trade domain I can’t > think of a use case where we don’t need > notarised and revocable credentials - things > that don’t get much of a mention in the w3c > specs. It’s why we use the Singapore open > attestation protocol > Steven Capell > > ====================================================== > Rabobank disclaimer: http://www.rabobank.nl/disclaimer > <http://www.rabobank.nl/disclaimer> > > <#rbnl#1898i> > > ------------------------------------------------------------------------ > > This email (including any attachments to it) is confidential, > legally privileged, subject to copyright and is sent for the > personal attention of the intended recipient only. 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Received on Tuesday, 22 December 2020 11:17:23 UTC