I am new to using oracle database. I want to encrypt data stored in oracle. I am using oracle 18c for this and using TDE(Transparent Data Encryption) feature for it. However, when I run select query on it, I am getting data in decrypted form. Is there anyway to get the output of select query also as encrypted. Also, it would be great if anyone could let me know good resources for the same as the the oracle official docs are not lucid.
TDE encrypts data on disk, and decrypts on the fly when data is accessed from the database.
After the data is encrypted, this data is transparently decrypted for authorized users or applications when they access this data. TDE helps protect data stored on media (also called data at rest) in the event that the storage media or data file is stolen.
What you described is another feature, called Data Redaction.
Here is an example with steps: https://oracle-base.com/articles/12c/data-redaction-12cr1