Passwords, PINs, voice recognition, biometrics. People have figured out hacks for all of those, so you’re better off using multiple security programs to safeguard your stuff. One such program that you should definitely consider is FaceCrypt. It’s an iOS app where your face essentially becomes the key to access your encrypted files and data.
The great thing about it is that aside from the main vault, you have the option to store files in drawers. Aside from biometric face recognition, you can also restrict access to these drawers by adding passwords and pattern access to make them more secure.