For more on this see "File Data Protection" and "Data Protection classes" in https://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/bu

For more on this see "File Data Protection" and "Data Protection classes" in https://www.apple.com/business/docs/iOS_Security_Guide.pdf https://www.apple.com/business/docs/iOS_Security_Guide.pdf . The default protection class is "Protected Until First User Authentication". This means that unless an app says something more specific, the key required to read a file is not available between reboot and the first time a phone is unlocked.