Hi Yong Sub Ji,
Q2) Authenticated==signed. The application image is signed with the selected key from PKI management. The processor does not allow to run unsigned application anymore. The attacker cannot change the application, because he does not have the private key.
Encrypted: application image is encrypted. If attacker read the external flash, there is no meaningful code.
Q1) See authenticated above. Authenticated mode is set in fuses and this is irreversible operation. Before the irreversible operation is done by the tool, there is confirmation dialog so you should know, what fuses were affected.
Q3) SEC tool does not configure JTAG security. I cannot help here.
Regards,
Marek
NOTE: If you find the answer useful, kindly click on [ACCEPT AS SOLUTION] button