Technical and Philosophical Question re: Digital Signatures

Question

My question is technical, but has a philosophical issue driving it.
Summary:
In Livecycle Designer ES2 (9), I would like to setup a form for digital signature that, once enabled for Reader, you can apply a digital signature without having to immediately save.  I know it can be done.  Example:  http://www.opm.gov/forms/pdf_fill/opm71.pdf
Technical:
How is this done?  Is it a setting of the signature field object?
Philosophical Underpinings:
1. I don't need the digital signature to be legally defensible, so I don't care if if the document changes after applying the signature, nor will any of the fields be locked down after signing.  However, the digital signature everyone at my company uses is the legally defensible type, so using it instead of digital ink is for simplcity's sake.
2. When most people sign a paper document, they usually sign, and THEN date.  The problem with Adobe et al.'s implementation of digital signatures is that you have to date, and THEN sign, or else the date field will usually be locked down after you are forced to save the document after signing.  I know that a date field is not required when using digital signatures, but you need to date field in case someone decides to print the form and sign the old fashioned way.
3. Because of this conundrum, I made the date field auto-populate with the signing date by applying javascript to the signature field that populates the date field upon signing.  The problem with that is that with Adobe forcing me to save the document immediately after signing, the date field does not populate because the signature applies to the version of the document that existed just prior to the signature being applied.  Since the date field wants to populate after signing, it is discarded.
Hence, I want to prevent Reader from forcing me to immediately save.  I am approaching this philosophical conundrum all wrong?
Signed,
Befuddled

Answer 1

"you can apply a digital signature without having to immediately save.  I know it can be done."
Whenever a signature is applied, the form gets saved. So, you can't apply a signature without having saved the form. Do some modifications in the form you have provided, save it and validate the signature. Validation would suggest that changes have been done in the form, so signature is invalidated at this stage. This effectively means that data has been changed in the form after signing making it unreliable so to say.
Since you are moving to digital signing in the form, I do not understand exactly why there's a need to manually enter the date after signing the form digitally. Once you sign the form, date automatically comes in the signature. This solves the purpose/use case that user needs to fill in the date. Ideally, you need to remove the date field from the form.
"I know that a date field is not required when using digital signatures, but you need to date field in case someone decides to print the form and sign the old fashioned way."
If you can't remove the date field from the form and want to have a simialr experience in digital world, the option is to write a simple script in the form which checks whether the date is filled in or not. If it's not filled in, abort the signing process and provide a message asking user to fill in the date.