VadimK wrote:have you heard of such strategy
Never.
VadimK wrote:what is the thought behind it
It's utterly stupid. Don't do it. 🙂
There are plenty of other steps you can take to secure the data, though. They range from ensuring the security of the server itself (firewalls, segregated user accounts, limited (if any) access to root, etc.) to data security (hash passwords with a user-specific salt, etc.) to the transportation of data (use HTTPS when remote user is submitting sensitive data to your server, etc.).