When you try to load an executable file or add-in, the software checks its security credentials, including its digital signature.
A digital signature is a block of information added to certain files to identify the originator and indicate whether a file has been altered since the digital signature was applied.
You can examine a file's digital signature through a chain of trust back to the root certificate issued by a trusted certificate authority (CA).
To access the digital signature for a signed file, do one of the following: