[E. Pluribus Unum]

MD5 has been employed in a wide variety of security applications, and is also commonly used to check the integrity of files.

[butterdezillion]

So if I scanned a document without editing it in any way, saved it as a jpeg or pdf, and posted it to my blog, could somebody who doubted its genuineness use MD5 to find that it has not been manipulated or edited in any way?

Of course, if I got a PDF from somebody else and they edited it in any way that would show, right?