Visual Signatures - interoperable electronic document signatures(Action #0045)

[Konrad Lanz <Konrad.Lanz@labs.cio.gv.at>]

(updated)

Hi Uri,
Dear fellow DSS-X Committee Members,

I hereby follow up on a proposal made by URI to Juan Carlos and myself
to continue with two profiles called

    - Visual Signatures
    - Interoperable Electronic Document Signatures (to be chartered)

instead of one.

In our view both profiles would be related to the visualization of the
fact that a document is signed. We would be interested in contributing
towards both of the profiles. As however Uri mentioned both profiles
seem to be distinct in their requirements and we agree to some extend.

Visual signatures - as understood by our proposal - will specify a
pattern of how visual signatures should look like and will have to have
fields that explicitly and legibly specify what method is to be used to
regain the verifiable electronic form from a document's visual
representation (probative value of printouts).
This implies a requirement for being able to put the SignatureValue into
the visual representation of the document.
The Visual Signatures Profile hence would after completing a
requirements phase be concerned with the specification of the visual
appearance of the signature and the required and optional fields in a so
called signature block.

It is a requirement for us that this specification is largely
independent of the document format.
The definition of optional inputs and terms should follow the
specification's concepts hiding the complexities of different data formats.

A basic processing for each document format could then be defined
mapping to visual representations following the required general visual
pattern.

Basic methods and their processing rules to regain the verifiable
electronic representation from some OCR scanned document could be
specified for simple and basic use cases like textual signatures. Such
methods for binary visual signatures that would have to be more specific
to the data format and require some archival dimension for images and
the like.

We would consider the special case of the method for regaining the
verifiable electronic form being an archival system an optional
requirement (or a non requirement).

It would be an intersection with a potentially very constrained form of
"Interoperable Electronic Document Signatures" fulfilling the
requirements for visible signatures (except for the SignatureValue).

The Interoperable Electronic Document Signatures Profile - as far as I
understand - would be concerned with bringing existing forms of
signatures specified in document format specifications into one DSS-X
profile. Its goal is to make existing functionality available in a
client server environment.


best regards
Konrad Lanz