A digital signature is a block of encrypted information added to certain files to identify the originator and indicate whether a file has been altered since the digital signature was applied.
Drawing files with digital signatures provide the following benefits:
- Recipients of drawings are provided with reliable information about who created a drawing.
- Owners of drawings are provided with reliable verification that a drawing has not been modified since it was digitally signed.
To attach a digital signature to a file, you must either have a digital certificate issued by a certificate authority, or you can create a self-signed certificate using one of several utilities.
You can examine a file's digital signature. This is important when you are working on collaborative projects, or if you receive an executable file. For drawing files, an icon is displayed on the status bar if a drawing file is digitally signed.
When you click the icon, you can verify information such as the validity of the signature, the name of the individual or organization that signed the file, and so on.
Supported Data File Types
You can attach a digital signature to the following file types with the DIGITALSIGN command:
- DWG and DWT files that are compatible with AutoCAD 2000 and later drawing-file formats
- DWS files (not available in AutoCAD LT)
Invalid Digital Signatures
A digital signature will become invalid for the following reasons:
- The file was modified after the digital signature was attached.
- The file was corrupted in transit or when the digital signature was attached.
- The digital certificate was revoked by the certificate authority.
Reapply a Digital Signature to a Drawing
In some cases, you might need to make changes to a drawing file and then reapply your digital signature. In those cases, use WBLOCK, specifying the entire drawing, and save it to a different file name for the sake of version control. Then apply your digital signature.