Encrypting data

By default, PostgreSQL internally encrypts sensitive data, such as roles' passwords. However, database users can also encrypt and decrypt sensitive data using the pgcrypto extension.

PostgreSQL role password encryption

When creating a role with password and login options, one can see the role's details in the pg_shadow catalog relation. Note that it is not recommended to use the following format to create the password because the statement can appear in pg_stat_activity or the server logs:

CREATE ROLE <role_name> WITH LOGIN PASWWORD 'role_password';

The passwords in pg_catalog are encrypted with a slat by default, as shown in the following example. Note how passwd for the a and b roles are different even though they have the same password:

CREATE ROLE a WITH LOGIN PASWWORD 'a';
CREATE ROLE b WITH LOGIN PASWWORD 'a';
SELECT usename, passwd FROM pg_shadow WHERE usename IN ('a','b');
 usename |               passwd
---------+-------------------------------------
 b     ...