| PdfDigitalSignature(X509Certificate2) | Creates a digital signature object that signs with an X509Certificate2, such as a certificate from the Windows certificate store, a smartcard or a USB token. RSA and ECDSA certificates are supported |
| PdfDigitalSignature(Byte, String) | Creates a digital signature object using PFX certificate data |
| PdfDigitalSignature(IExternalDigitalSignature, Byte) | Creates a digital signature object that signs with a private key held outside the application, such as a hardware security module or a cloud key service. The library prepares the signature, calls Sign(Byte) for the signature value and embeds the result |
| PdfDigitalSignature(String, String) | Creates a digital signature object using PFX certificate data read from a file |