I have found that if I use transformable type of attributes and NSXMLStoreType my data is encrypted, that is attributes that has been of transformable type, are not readable. There is no need of doing anything else, no code is required. Please note that I am working on OS-X application that uses core data.
However, if I change my store type to NSSQLiteStoreType, that is not the case.
I can open the database with sqllitebrowser, select the transformable field, and If I click on export button, in the generated text file, I can read the value normally, that is the value (data) is not encrypted.
I have asked the same question about 4 months ago and I get no answer.
Also, I have found this post here on stackoverflow.
You can encrypt individual properties in your Core Data model entities by making them transformable properties, then creating an NSValueTransformer subclass which will encrypt and decrypt the data for that property.
Unlucky for me, the author of the answer, @Brad Larson, didn't provide an simple example of how this can be done.
Can anyone provide any sample code of how I can encrypt transformable properties so that It' cant be readable in any way?