Is there a way to protect inside a database files or folders from being read from others? Or made them invisible? I know that I can protect with a password an entire database, but is there another solution to protect parts of it?
Thank you
Not at this time.
The most secure encryption at this time would be to save a database containing sensitive information within an encrypted disk image.
As DT Pro 2 and DT Pro Office 2 allow multiple databases, a strategy to provide maximum protection for sensitive information would be to put that information within an encrypted disk image, and to open it only when that information is needed. While open, the content can be searched either for that specific database or across multiple open databases. Make sure that Spotlight searching isn’t turned on (File > Database Properties) for such a database.
Note: Please don’t forget your password for such encryption, as there’s nothing we can do to help you recover the data in that case. 
Remember also that, in the real world, most ‘hackers’ who gain access to sensitive information on a computer do so not by sophisticated technical techniques to crack encryption, but by human engineering – either persuading the victim to give them the password, or trying out the kinds of simple passwords most people use, such as a family member’s birthdate, the family dog’s name, etc. Especially in the PC world, installing keyboard trackers to capture password entry by the user, then send such information to the hacker, is widely used by the bad guys, so that encryption of data such as bank account or credit card data becomes meaningless.
If you use a Macintosh your odds of having your credit card number stolen each time you use it to pay a restaurant or retail store bill are enormously greater than the risk when using your credit card for an online purchase on a secure Web site – unless hackers get access to the merchant’s own database.
Yes, there are bad people out there. Take precautions with sensitive information. But don’t be so overcome by paranoia that, for example, you are unable to cross the street to buy food, and so starve to death.
Thank you for your length answer. You are very kind! It would be nice to have a way to protect files on a single base. But your solution if fine.
Have a nice one.