Just as no paper document is secure from forgers. Actually, the typical birth certificate's document security is laughable compared to that of US currency.
With a birth certificate, the ultimate recourse is to check with the alleged issuer to confirm or refute validity. An HTTPS server would reduce that process to a single click. The ability to check with the issuer easily would reduce the likelihood of fraud way below what it is having to rely on a paper document's physical appearance — whether it has a raised seal, whether the issuer's signature stamp looks right, etc. What a joke!
Banks, brokers, and credit card companies all use HTTPS servers successfully. Their rate of fraud is not zero, but it is very low. Way lower than the government's, as Newt likes to point out.
Second, it would be way too easy to pay some one off on the inside to change and/or replace whatever you wanted to with another file.
No easier than it is now.
Heck, I found a clip from an old article when I was hit by a Sears truck when I was 4 years old in my Mom's old keep sakes.....from 1965
Funny thing is, it's on the Internet too under Ancestry.com, but I have a paper copy to compare it to and verify its legitimacy. If everything is digitized and paper is eliminated, well you can surly see the problems with that.
Why do you think they might want to eliminate paper ballots?