I want to implement security in my app, and I'm thinking of this idea:

The security data will be stored in a memo field and encrypted.

I would create a row for default values:

login, allow			<-- User can log in
customers, add, allow		<-- User can add customers
customers, edit, allow		<-- User can edit customers
customers, remove, deny		<-- User cannot remove customers

Then any variations from the default for that user are copied to the user record:

customer, 87, edit, deny	<-- The user can edit all customers EXCEPT customer 87
invoice, 125, view, deny	<-- The user can view all invoices EXCEPT invoice 125

Then, I could simply decrypt the data and pull all rows with 'customer' for a specified PK and
know any restriction for that user related to the customer.

I'm open to suggestions

Thanks