Create a confidentiality level and add it to the confidentiality matrix as follows: In the example below, the JSON format third argument requests that confidentiality objects belonging to 'level1' are encrypted. Specify NULL if you don't want anything. Refer to "B.2 Confidentiality Level Manipulation Functions" for the content of the request.

select pgx_create_confidential_level('matrix_foo', 'level1',  '{"encryption_algorithm":"AES256"}', 'The strongest encryption is required for this level.')

You can also check the added confidentiality level by referring to the pgx_confidential_level table.