Depends on what you mean by "authentic". It is, of course, an authentic PDF. The information in it -- from the place and date of birth to the names, to the attending physician -- is, as far as anyone has proven, authentic (why fake a birth certificate then populate it with true information???). It has been vetted and certified and declared authentic by the Hawaii DOH over and over again -- unless you're going to accuse the HDOH of complicity (THERE'S your conspiracy theory). And all we have to the contrary is this (not-very-)long line of self-styled "experts" trotted out by WND (to paraphrase Dorothy Parker, if all the WND document experts were laid end-to-end -- I wouldn't be surprised), everyone of which has earned a fail. One of Corsi's so-called PDF experts didn't even know what "PDF" stood for.
This Mara Zebest is just the latest example. Corsi and birthers can expound all they want on the ins and outs and ups and downs and sideways of Adobe software. You guys can trot out every Adobe expert in the world. It's all irrelevant. You wanna know why? Because the damn thing wasn't created with Adobe! I repeat for the synapse-impaired: the PDF the White House posted WASN'T CREATED WITH ADOBE. It was created on a Macintosh using Quark.
How do I know? It says so. Load the thing up in any PDF viewer, click on File and go to Properties (in Photoshop it's File/File Info...). Right there: "Producer: MAC OS X 10.6.7 Quartz PDFContext".
So, this Mara Zebest, this Adobe expert with her three-page resume of unimpeachable Adobe credentials, is utterly irrelevant. Worse, it apparently never even occurred to this world's most brilliant Adobe genius to check the file properties before running off on her utterly useless Adobe tangent. That's not just fail -- that's EPIC fail.
It's like trotting out a ballistics expert to expound on bullet trajectories and calibers and rifling patterns and composition when in fact the victim is riddled with stab wounds. And worse, nobody from the prosecution even seems to have noticed that knives are not guns. Somebody, somewhere, is just not firing on all cylinders.
Further, Zebest is NOT an expert in document forgery. She is an expert in Adobe software. The most her expertise can do is to prove that there are "anomalies" in the PDF file inconsistent with the way Adobe software does things (did I mention the White House PDF wasn't created with Adobe?). That's where Zebest's expertise ends, and that's as far as any legitimate Adobe expert with an ounce of self-respect will go. An Adobe expert has no more expertise -- and no more business -- trying to connect the dots from "anomaly" to "forgery", than a ballistics expert has in determining whether a gunshot wound is conclusive of murder.
So now Corsi calls Zebest up, offers to fly her out to DC for this press conference, spring for her hotel room, maybe even drop a bit of cash in her pocket for her trouble, so she can propound on the fakeness of the White House BC. She could have said, "Sorry, no. You need a Quark expert. I specialize in Adobe." She didn't. She accepted the invitation. Now, either she knew it wasn't an Adobe creation or she didn't. If she did, she was dishonest and unscrupulous. If she didn't, she's incompetent, her resume notwithstanding. I don't know which, and I really don't care. Either way, she damned herself before she even stepped up to the microphone.
And then, this Adobe expert -- and I don't doubt her credentials, only her testimony -- gets up and says absolutely nothing new. "Look -- links!", she says. "Layers! Pixelation! Color! That's just not normal." ("Not normal," she means, "for Adobe." Did I mention the file was created in Quark?) I don't care who says it, that kind of silliness was discredited long ago.
Don't believe me. Don't believe her. Do your own research. Go download Adobe Acrobat -- you can get a free trial version from the Adobe website -- turn on OCR and scan your own birth certificate. Links, layers and pixelation out the wazoo. Again, don't take my word for it -- do your own research. I did. I listened to Zebest (and WND's other experts), then attempted to verify their claims and, as far as I could see, their claims didn't verify. Don't scream, "She's an expert! Who are you?" (google "appeal to authority"). Do your own research.
Just for accuracy's sake: It wasn't created with Quark, which is page layout software. Quartz, on the other hand, is part of the native Mac OS X display software. It's also part of what lets the Mac write PDF files from any application. So, from what I read, the fact that the creator is listed as "Quartz PDFContext" probably means the scan was opened in some Mac program from which it was "printed" to PDF, or opened in the Mac's native graphics viewer (Preview) and exported as PDF.
Note that Preview has a "reduce file size" Quartz filter option. Some argue that its operation would account for many of the "anomalies" in the birth certificate.