The standard answer for enforcing user-based data entitlements in Tableau is to use Row Level Security, where the user is authenticated in Tableau Server and then tied into an “entitlements view” in the database so that the user only ever sees data they have access rights to.
However, we are very often asked about passing parameters in to the viz to filter down information directly at load time, often driven by an application that Tableau vizes are embedded in. This post is about a few methods of implementing this behavior, and the security implications of each of them.
Basics of Security
Everything must be HTTPS
I’ll start by saying, to do any of this securely, you need EVERY resource you are working with to be using the HTTPS protocol (latest TLS version). If anything is not HTTPS, you could be passing important information in the clear.
Using URL Parameters to set a Filter directly is NOT SECURE
You can use the URL Parameter syntax to directly set the values for a Filter on any field, but this is completely insecure. Why? Because the following two methods will clear any filter and reveal all of the rows of data. Unless you have the JS API turned off, there is no way to prevent this.
Sheet.applyFilterAsync(fieldName, "", tableau.FilterUpdateType.ALL);
Tableau Parameters are the (potentially) secure way to make an adjustable Data Source Filter
The only way to prevent a user from resetting a filter value is by making it a Data Source Filter. Thankfully, you can use a Calculated Field for the Data Source Filter. If you use Tableau Parameters in the Calculated Field, the Parameter value(s) can be set to change what is filtered, and you will have a Data Source Filter that cannot be altered by the JS API (or the end user).
However, there are quite a few considerations to make this a truly secure method for setting filter values: