Digitally signing a model or file can be used to indicate approval of the design. Another user can then detect the signature, verify the signer’s identity, and verify that the design has not been changed since it was signed. Model-specific signatures are displayed graphically in the context of the design. Multiple signatures can be affixed to a single file or model. Hierarchical signing is also supported so that one signature is dependent upon prior signatures. A signature can cover the content of a model or file and all of its references including DGN and DWG references.
Among other key features, signers can use cells to represent signatures with arbitrary graphics; an API is defined to allow applications to customize where signatures can be placed and how a signer’s identity is authenticated; and there are several ways users can detect valid signatures to prevent spoofing.