Cach Sign document
Add and Verify Digital Signatures in PDF Documents using Java
Cach lay certificate from USB Token
https://stackoverflow.com/questions/34166304/accessing-windows-certificate-store-certs-via-java
Kiem tra Windows co chua token khong?
https://stackoverflow.com/questions/25257458/reading-a-pfx-file-from-usb-token-with-java
Ky dien tu bang commandline. Open source
https://github.com/AlessioScarfone/Java-Digital-Signature
Chrome Extension for signing documents
https://github.com/AlessioScarfone/Digital-Signature-Chrome-Extension
