# Digital Signatures



## momech (Mar 2, 2011)

Just wondering if anyone has experience with using digital signatures for secure verification when submitting electronic documents (drawings, specs, etc.) in .pdf format.

The Missouri Code reads, "(3) In addition to the personal seal, the licensee shall also affix his/her signature and place the date when the document was originally sealed, at the minimum, to the original of each sheet in a set of plans, drawings, specifications, estimates, reports and other documents which were prepared by the licensee or under his/her immediate personal supervision. The term “signature,” as used herein shall mean a handwritten identification containing the name of the person who applied it; *or for electronic or digital documents shall mean an electronic authentication process attached to or logically associated with the document. The digital signature must be unique to, and under the sole control of the person using it; it must also be capable of verification and be linked to a document in such manner that the digital signature is invalidated if any data on the document is altered*."


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## willsee (Mar 2, 2011)

We perform digital signatures if the owner is going to be gone. The designers make it a pdf block in CAD and we just paste it in.

This is in Kentucky and at my last job I believe we did it for Louisiana as well.


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## momech (Mar 2, 2011)

willsee said:


> We perform digital signatures if the owner is going to be gone. The designers make it a pdf block in CAD and we just paste it in.
> This is in Kentucky and at my last job I believe we did it for Louisiana as well.


So what provides the verification that nothing has been changed in the drawing? Do you use a 3rd party like VeriSign, GlobalSign, etc?


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## wilheldp_PE (Mar 2, 2011)

I use a .jpg signature and seal to sign/seal my reports now. When I worked for an A/E firm, we used .dwg versions the signature, seal, and date. They weren't 3rd party verified...we were just responsible for keeping our files secure so that people didn't use them to sign things we didn't approve. When submitting drawings/reports, we only send .pdf electronic versions so that our signature/seal couldn't be extracted.


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## jeb6294 (Mar 2, 2011)

We use .pdf's a lot here since we're so removed from everyone. We can digitally sign .pdf's but we have encoded ID cards that require you to put in your PIN so I don't know if you can do something like that in the "real world". We have been told that the Government has officially determined that a digital signature is just as good as a hand signature.


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## Supe (Mar 3, 2011)

The gentlemen who used to approve our procedures uses a digital signature. You can only copy it with a screenshot, but if you try to alter the PDF or even use the "combine" feature, it disappears and flashes a warning.


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## wilheldp_PE (Mar 3, 2011)

There are some states that require a wet stamp and signature and there are others where digital is alright for one or both. It's a big fat pain in the ass to wet stamp and sign a 100+ sheet drawing package in triplicate.


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## IlPadrino (Mar 3, 2011)

wilheldp_PE said:


> I use a .jpg signature and seal to sign/seal my reports now.


A digital signature (if it's really a digital signature and not just a digital facsimile of an image of your inked signature) must be able to establish authenticity (the signer is who he says he is), integrity (the document hasn't been changed since the signature was applied), and non-repudiation (the signer can't deny having been the one to sign the document). Public-Private keys are the standard for digitally signing documents and the private keys can be stored on a smart card (hardware) or as a file on the computer (software).

The U.S. Government has gone to a standard Common Access Card (smart card) to digitally sign - it's really quite convenient. The only problem I've run across is that some organizations are adamant a document isn't signed if there isn't a wet signature. I can almost always get around it by adding a graphic to my digital signature that looks like my ink signature, but every now and again some lawyer will insist on the wet - so I trace over the graphic with a fat sharpie. One of these days, I'll try to highlight over it and see what happens.


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## momech (Mar 3, 2011)

IlPadrino,

That was my understanding. I'm looking for my what my options are regarding using a true "digital signature."


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## jeb6294 (Mar 4, 2011)

IlPadrino said:


> wilheldp_PE said:
> 
> 
> > I use a .jpg signature and seal to sign/seal my reports now.
> ...


That's what I go with...I scanned in a copy of my actual signature so when I sign a form it's my signature with all the official mumbo jumbo info it adds.


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## IlPadrino (Mar 5, 2011)

jeb6294 said:


> IlPadrino said:
> 
> 
> > wilheldp_PE said:
> ...


And using a .png is much better than a .jpg - a transparent background looks much more realistic than a white background. JPEG doesn't support transparent backgrounds.


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