As you now know, databases with digital signatures are exceptions to the macro setting checks. That is, if a database is digitally signed, it can be opened regardless of the macro setting.
Before you tackle creating and using digital signatures, however, let's briefly review ACCDB files. Access 2007 introduces a new file format called ACCDB. These files include additional features for the Access database engine and are the default file format created in Access 2007, but they do not support digital signatures—at least not in the sense that you were becoming accustomed to in Access 2003. For ACCDB files, Microsoft has introduced a new feature called Signed Packages that enables you to compress a database and sign the compressed file. You'll see more about this feature later in the chapter.
Okay, back to digital signatures. So, what is a digital signature and how do you create one?
You have probably seen various forms of digital signatures or digitally signed programs while browsing the Internet or installing software. Typically you see a security warning dialog box that contains information describing the purpose of the digital certificate used to sign the program, the date and time the certificate was published, and who published it. Some certificates permit you to obtain more information about the program and/or the publisher. After reviewing the information about the certificate, you can accept the certificate or reject it. If desired, ...