data redaction,

i)  what privilege does application user needs to  see the actual data in application screen after dbms_redact   has been used to redact the column? Or, how to enable application user/particular user to  see the data in application screen?

ii) for dbms_crypto , we need to decrypt the data to see in screen, is there  similar process   for dbms_redact  ?

ii)  for column level encryption is there any way  other    than dbms_crypto package?

iv) Can anyone suggest use-case when to use redaction not encryption in  column level using dbms_crypto?

v) how does authorized user see data after data redaction, data masking, encryption, subletting.