2004

784 | Chapter 27 Protect and Sign Drawings
View Drawings with Digital Signatures
Digital signatures provide an electronic means of validating (verifying the
authenticity of) signatures that are attached to drawing files.
A digital signature identifies an individual or an organization through a
digital ID (certificate), and enables you to validate the file. Validating a file is
especially important when you are working on collaborative projects or
transmitting files over the Internet. You can validate a digital signature in
either AutoCAD or in Windows
Explorer.
Using digital signatures feature, you can obtain the following information
about signed files:
■ Whether the file was changed since signed.
■ Whether the signers are who they claim to be.
■ Whether the signers can be traced (thus preventing forgery).
A digital signature is determined to be invalid for the following reasons:
■ The file was corrupted when the digital signature was attached.
■ The file was corrupted in transit.
■ The digital ID is no longer valid.
Note If you want to retain valid digital signature status, do not add a password
or otherwise modify or save a file that already has a digital signature attached.
Make modifications, such as adding passwords, before signing the file. Signature
information does not remain intact if you modify, save, or export drawing data.
View Digital Signature Details
When you receive a file that contains a digital signature, you can check
whether the file was modified since it was signed, and other information.
An icon is displayed in the status bar when a file contains digital signature
information. When you click the icon, you can verify the following
information:
■ Validity of the file
■ Whether the file was modified since it was signed
■ Individual or organization that signed the file
■ Time stamp and comments attached to the file
■ Issuer (certificate authority) of the digital ID
■ “Valid to” and “valid from” dates for the digital ID