[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]
Subject: RE: [egov] Re: Secure Workflow. Was: [egov] "Dry" and "Wet" signatures - A definition
I think that it depends upon the goal and whether it is within the
Charter of the TC. If the goal is to create a new standard around which
applications can be developed for a specific purpose, such as
browser-based web signing, as Anders proposed, then I think a new TC or
another TC must do the work, as the Charter of this TC is limited to
policy matters such as recommendingf best practices and OASIS XML
standards to governments but not the creation and testing of XML
standards as such.
> -------- Original Message --------
> Subject: RE: [egov] Re: Secure Workflow. Was: [egov] "Dry" and "Wet"
> signatures - A definition
> From: "Peter F Brown" <peter@justbrown.net>
> Date: Tue, August 30, 2005 1:18 am
> To: "'Anders Rundgren'" <anders.rundgren@telia.com>, "'Ed Chase'"
> <chase@adobe.com>
> Cc: "'eGov OASIS'" <egov@lists.oasis-open.org>
>
> I disagree that the central concern is the server-end of the pipeline:
> the
> sender should be the focus: it is "their" data that is at question in
> most
> cases, and they should have better control of the process, for example
> seeing the mechanism for provision of user data as mirroring a classic
> SOA
> (see attached outline - please note IPR declaration)
>
> But I digress: I echo Duane's question: are we looking to spin-off a
> new TC?
>
> Best regards,
>
> -Peter
>
> -----Original Message-----
> From: Anders Rundgren [mailto:anders.rundgren@telia.com]
> Sent: 29 August 2005 23:43
> To: Ed Chase
> Cc: eGov OASIS
> Subject: Re: [egov] Re: Secure Workflow. Was: [egov] "Dry" and "Wet"
> signatures - A definition
>
> Ed,
> In your description of the purchasing process, you left out the
> information
> (workflow) system. In my opinion, information systems today constitute
> the
> core of IT, and should due to this influence how you structure and
> control,
> not only data, but processes, roles etc.
>
> By using client-based PKI security, you can indeed extend
> authentication
> beyond your own systems as your rightfully claim. The dark side of
> this
> superficially very tempting perspective, is major inflexibility, high
> costs,
> limited scalability, privacy issues, and a multitude of "very promising
> PKI
> pilots".
>
> If we again take the US federal agencies (who have toiled with FPKI for
> more
> than a decade), they for some reasons, AFAIK, to date do not publish
> certificates, in spite of being a prerequisite for handling encryption
> the
> way you describe. SSL/TLS has due to this become the de-facto way of
> encrypting transactions between organizations, at least for POs.
>
> Apparently even some US public sector entities have recently begun to
> realize that the end-to-end PKI paradigm is not delivering, which can
> be
> seen in the following document:
> http://middleware.internet2.edu/pki05/proceedings/kailar-phinms.ppt
> <http://middleware.internet2.edu/pki05/proceedings/kailar-phinms.ppt>
> which, somewhat ironically, was initially shown in NIST's facilities,
> the
> very home of FPKI.
>
> My proposed charter for a WebSign standardization effort is therefore
> targeting a world "controlled" by information systems. Furthermore, I
> would
> favor a scheme that addresses the volume market which is signing off
> day-to-day tasks like on-line bank payments, PO attestations, income
> tax
> declarations, and doctor appointments. It does in no way have to stop
> there, but this is where it should start.
>
> regards
> Anders Rundgren
> Working for a major US computer security company but here acting as an
> individual
>
>
> ----- Original Message -----
> From: Ed Chase <mailto:chase@adobe.com>
> To: John Messing <mailto:jmessing@law-on-line.com>
> Cc: Duane Nickull <mailto:dnickull@adobe.com> ; eGov OASIS
> <mailto:egov@lists.oasis-open.org> ; Anders Rundgren
> <mailto:anders.rundgren@telia.com>
> Sent: Monday, August 29, 2005 20:08
> Subject: Re: [egov] Re: Secure Workflow. Was: [egov] "Dry" and "Wet"
> signatures - A definition
>
> John -
>
> It seems that you're suggesting that you can establish authenticity
> without
> identity. I would disagree. At some point you have to establish trust
> with a
> system, individual, or organization through some means - whether this
> is
> internal authentication or PKI digital ID it's the same concept. Trust
> has
> to be established either explicitly or implicitly. PKI signatures just
> offer
> the opportunity to extend authentication beyond your own systems. While
> an
> ebXML registry could certainly categorize the information in the
> messages,
> it doesn't really address any issues of trust between the parties.
>
>
> With regard to secure transactions & PKI -
>
> For transactions like the purchase order example that start internal
> and
> later become external, why not use PKI from the start and employ
> policy
> mapping between organizations or a bridge? Certificate policy mapping
> (for
> limited sized communities) or a PKI bridge would give the trading
> partners
> interoperability on both the authenticity and security fronts. How
> about
> something like this:
>
> 1) Include PKI policy-mapping with business partner agreements and/or
> take
> advantage of a PKI bridge.
> 2) Create a your forms in PDF or an XHTML document variant that's based
> on
> your industry standard for exchange - UBL or whatever.
> 3) Users complete the form or application and sign both presentation
> and
> data with their digital identity. If it's a PDF, the signature is
> embedded
> within the document, and you can also embed the revocation status of
> your
> credential at sign-time for long-term validation.
> 4) Encrypt the document for the recipient's specific digital ID if
> required
> and send the document
> 5) The document is protected regardless of transport. Having a PKI
> relationship with your trading partner allows your signatures to be
> validated by the recipient.
>
> The majority of this can be automated. Signing and validation can be
> server-centric if required. Everything you need for auditable long
> term
> validity is self contained within the document and possessed by both
> parties. The PKI layer is also self-contained and well removed from
> the
> process. You don't have to worry about transport or individual
> authentication requirements for different trading partners.
>
> Ed
> --
>
> <http://www.adobe.com> Ed Chase
> Worldwide Standards
> Adobe Systems, Inc.
> chase@adobe.com
> 703.883.2830
>
> John Messing wrote:
>
>
> A secure audit trail can be accomplished with tamper-evident
> technologies and may have value even when a logical association with
> a
> human or legal entity as a signer in a conventional sense is not
> necessary or desired (e.g., to document log events securely). Where
> such logical association with signers is required for purposes of
> legal
> enforceability, then it can be considered as a subset of the secured
> workflow generally. Componentizing documents into strings and
> metadata
> can overcome many of the archival issues that have been alluded to
> but
> rarely confronted directly. Tamper-evident technologies need not
> include PKI, or even traditional digital signatures, but should take
> into account recent Chinese contributions to hashing technologies
> and
> their weaknesses. ebXML repository technology may prove to be very
> useful in this context. Whether retention of copies of original
> documents in original format will be required remains to be seen.
>
> The American Bar Association adopted guidelines in August 2005 for
> Court
> Automation that incorporate many of these notions.
>
> John Messing
> American Bar Association Science and Technology Law Representative
> to
> OASIS and LegalXML-OASIS.
>
>
>
> -------- Original Message --------
> Subject: [egov] Re: Secure Workflow. Was: [egov] "Dry" and
> "Wet"
> signatures - A definition
> From: Duane Nickull <dnickull@adobe.com>
> <mailto:dnickull@adobe.com>
> Date: Mon, August 29, 2005 8:02 am
> To: Anders Rundgren <anders.rundgren@telia.com>
> <mailto:anders.rundgren@telia.com>
> Cc: eGov OASIS <egov@lists.oasis-open.org>
> <mailto:egov@lists.oasis-open.org>
>
> Anders:
>
> I understand your intent better after this email. My points
> are:
>
> 1.Steps 2 and 3 of your secure workflow below are the only
> methodology
> that should be employed. One should not presume that any
> "document"
> will never be modified and always perform some type of
> checksum()
> operation before validating a signature. The signed content
> should
> always be auditable.
>
> 2. There is no need to stop at the document level, DSig
> methodologies
> are significantly complex today, even allowing signing of a
> partial
> sub-set of a document. Therfore, documents can contain both
> mutable and
> immutable content. Logically, if you only look at a
> "document" and some
> part of it is mutable, you always have to declare the entire
> document
> mutable. I would advocate migrating from "document" to
> "content" or
> components that make up a document in the thinking.
>
> 3. An archive, checksum() implementation that provides a
> view of any
> changes is also preferrable since not all changes to
> previously signed
> content may be deemed to invalidate a signature. This
> concept of
> legality and material vs. immaterial changes to a contract
> exists in
> many legal jurisdictions. For example, if you sign a
> contract then
> later change your postal code, that is probably insufficient
> to
> invalidate the entire contract.
>
> Duane
>
> Anders Rundgren wrote:
>
>
>
> Duane,
> I may have been unclear but my intention was not
> alluding that there
> any major security issues hidden here.
>
> For a universal signature/document system like
> Adobe's, these terms
> may indeed be flawed (or not apply) as you say. A
> web-only signature
> scheme may though be differently architected and in
> such schemes the
> terms Dry and Wet terms are not entirely wrong.
>
> My personal preference is that a possible standards
> effort should only
> target Dry signatures as these (in a web environment
> NB), are more
> flexible due to the separation of "user views"
> (static documents in
> arbitrary formats), signatures, and possible
> associated transaction data.
>
> *Secure Workflow*
>
> A further complexity is that few organizations
> including the US
> federal agencies have yet begun to look on how
> secure messaging is to
> be accomplished on a wider scale except by using
> e-mail.
>
> However, e-mail has huge limitations for
> sophisticated (automated and
> interactive) workflow compared to web based systems
> where the
> "transaction" and the "view", are typically not
> using a common
> representation. The latter of course has a major
> impact on how
> signatures can be utilized.
>
> I have personally "toyed" with a number of use cases
> in order to clear
> the picture for myself (to begin with...). One
> simple but still
> pretty universal such use-case is the e-purchasing
> process where one
> or more employees are running an internal workflow
> system where a
> purchase request is, after proper authorization,
> converted into a
> purchase order and sent to a supplier.
>
> My own take on the aforementioned e-purchasing
> process and using the
> web is as follows:
>
> 1. The user is (when he considers him as ready),
> presented a completed
> requisition proposal in for example HTML or PDF,
> which he is requested
> to sign and submit. In the background the actual
> data is usually
> held by the web server session in a
> "computer-friendly" format.
>
> 2. After signature validation etc by the workflow
> system. the
> requisition is archived together with the user's
> signature for
> possible /future references/
>
> 3. Assuming the user is the final authorizer, a
> purchase order is now
> created in a B2B-network specific format (like UBL
> or EDI), based on
> the requisition data (kept in the web session).
>
> 4. The completed purchase order is then archived in
> a table linked to
> the signed requisition for possible /future
> references/.
>
> 5. Finally, the purchase order is secured[*] and
> sent away for
> fulfillment in a B2B-network defined way
>
> Steps 2-5 are automatically performed by the
> workflow system
> (server). Except for user signatures,/ the scheme
> above is the
> de-facto standard way of performing B2B operations/.
>
> regards
> Anders Rundgren
> Working for a major US computer security company but
> here acting as an
> individual
>
> *] This part is unfortunately a major problem for
> many people working
> with PKI as /it is really the workflow system that
> creates, secures,
> and sends purchase orders to external suppliers/.
> Due to this,
> existing [/and widely used/] B2B schemes are almost
> exclusively
> non-secured or are using shared secrets as such
> schemes (/in spite of
> being completely inferior/) seem to pass without
> major consideration,
> while "signing PKI-servers", immediately brings in
> the legal
> department ("a machine has no will or legal power"),
> the security
> experts ("this is violating end-to-end security"),
> and forces most
> such efforts into a dead halt. A maybe vane hope,
> is that these very
> interesting issues will be properly "aired" when/if
> a web signature
> standards process is launched.
>
> ----- Original Message -----
> From: "Duane Nickull" <dnickull@adobe.com
> <mailto:dnickull@adobe.com> <mailto:dnickull@adobe.com> >
> Cc: "eGov OASIS" <egov@lists.oasis-open.org
> <mailto:egov@lists.oasis-open.org>
> <mailto:egov@lists.oasis-open.org> >
> Sent: Thursday, August 25, 2005 19:41
> Subject: Re: [egov] "Dry" and "Wet" signatures - A
> definition
>
>
> Anders et al:
>
> I will suggest you may want to think about this
> differently. Many
> signature mechanisms work in a way that mitigate the
> problem you are
> hinting at without having to make this distinction.
> Attempting to make
> two classes of signature for mutable vs. immutable
> content is flawed IMO
> since you would have to fully understand every
> possible way a document
> or content *might* be modified. This is simply
> beyond the grasp of any
> group of people since there are so many variables
> (metadata changes,
> versions, file names etc.) plus you are relying on
> third party vendor
> statements to be 100% accurate.
>
> A better methodology is to stipulate that at the
> time of signing, a hash
> is made of the exact content using state of the art
> algorithms and if
> the content later changes, the signature block is
> flagged to indicate
> that there have been changes since it was signed and
> let the actor
> decide how they want to proceed. Adobe Acrobat's
> signature method works
> this way. If for any reason, any of it changes, the
> signature
> presentation is flagged to indicate such. This
> method was perfected by
> Adobe, RSA, Entrust, VeriSign, GeoTrust, and
> ActivCard. There is a lot
> of information available on this from our website:
> http://www.adobe.com/security/digsig.html
>
> The attached file was signed, then changed to
> demonstrate this. If you
> go to the signature field, you can click on the
> triangle symbol by the
> green check mark. It will open a dialog window that
> tells you the
> document is still the same, but the values
> themselves have been altered
> since (this is important to distinguish between).
> If you select
> "signature properties", you get even more
> information.
>
> Under the summary, the window will note any changes.
> If you select the
> "document" tab, a modification details window
> appears. There is a
> button that allows you to generate a change log to
> compute modifications
> subsequent to signing the document. You can also
> select 'View Signed
> Version' to see the version that was signed and
> compare the two documents.
>
> I agree that mutability detection algorithms are
> complex. Our mechanism
> was the result of numerous companies collaborating
> with customers to
> ensure all legal and technical problems were solved.
> This was a
> somewhat lengthly process.
>
> Best wishes.
>
> Duane
>
> Anders Rundgren wrote:
>
>
>
> Dear list,
> In a previous posting where I referred to
> some discussions concerning
> a possible Web Sign standards effort within
> OASIS, "Dry" and "Wet"
> signatures were mentioned. Several off-list
> messages indicate that
> these terms need a proper explanation.
>
> This comes to no big surprise as these terms
> have actually been coined
> by myself in the absence of an established
> terminology in this
> actually rather virgin field.
>
> *"Wet" web-signatures
> *An editable document, be it an MS Word
> document or an HTML form with
> edit fields, radio buttons etc. is filled-in
> and signed by the user
> and then sent to the service provider.
>
> *"Dry" web-signatures*
> The user is (after an arbitrary interactive
> process with a service
> provider), presented, a static (read-only)
> document and is requested
> to sign it in order to indicate
> "acceptance". Since the document
> actually comes from the service provider,
> the result sent to the
> service provider is typically only a
> detached signature of the shown
> document.
>
> *Further comments*
> These schemes represent two different
> schools, one which tries to
> mimic the existing paper form world, while
> the other scheme is more
> aligned with how the web is currently used.
>
> *Implications*
> Superficially these schemes may appear
> similar, but that is indeed not
> the case; there is probably a 10-to-1
> difference in complexity unless
> you restrict "Wet" signatures to only
> support a single document
> format. The reason for this increase in
> complexity is that each
> document format has its own native signature
> format (or has no defined
> signature format at all), as well as its own
> input data validation
> scheme. Using "Dry" detached signatures,
> you can achieve the same
> thing as S/MIME does, namely document format
> independence with respect
> to the signature process (except for some
> trivial canonicalizations).
> Possible input data validation is assumed to
> have been carried out in
> earlier phases of a web session, using
> standard web methodology.
> There are numerous other implications as
> well concerning the use of
> "Wet" and "Dry" signatures, but these are
> far outside the range of an
> e-mail posting.
>
> Anders Rundgren
> Working for a major US computer security
> company but here acting as an
> individual
>
>
>
>
> ----------------------------------------------------------------------------
> ----
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe from this mail list, you must leave
> the OASIS TC that
> generates this mail. You may a link to this group
> and all your TCs in
> OASIS
> at:
>
> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe from this mail list, you must leave the OASIS
> TC that
> generates this mail. You may a link to this group and all
> your TCs in OASIS
> at:
>
> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php
>
>
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe from this mail list, you must leave the OASIS TC that
> generates this mail. You may a link to this group and all your TCs
> in OASIS
> at:
>
> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php
>
>
>
>
>
>
>
>
>
>
> ---------------------------------------------------------------------
> ---------------------------------------------------------------------
> To unsubscribe from this mail list, you must leave the OASIS TC that
> generates this mail. You may a link to this group and all your TCs in
> OASIS
> at:
> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php
[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]