If your certificate file doesn't have a password, then this option will be hidden
There is no password, because the certificate is stored on smart card, rather than PKCS#12/PFX file.
Starting with version 11.2 of Advanced Installer we have added an improvement so that multiple files can be signed at once during build process
I'll take a look into a new version.
I know, I can't dictate or recommend you how your product must work, but I have several thoughts, which you can forward to your development team for further consideration.
I made a little research and found that you use (as of AI10.9) a separate .exe file to sign files. Obviously that this .exe file is executed each time the file is signed and looses the handle to a private key each time the process ends. If you are using .NET framework, then you can use direct .NET calls to create and attach authenticode signatures. Otherwise, it is a bit more complicated, but it is possible to use native CryptoAPI functions to do this. In this case, you acquire the handle only once and use it for subsequent calls without having to prompt the PIN until the handle is released.
As a workaround, in order to avoid this behavior (if you are allowed to) you can import your certificate in the Certificate Store and use it from system store or you can copy it on a local path and use it from disk.
it is not possible. It is a main function of smart card -- private key never lefts the card and it is never exposed to an application, all cryptographic operations are performed within the card.
In any way, thanks for your help.