Named rights
Only the WORKFLOW named right is specific to workflows: it lets you create, start and stop workflows. Reading rights on the workflow file are required for the named right to be applicable. For targeting workflows, the reading right on the Profiles and Targets file is necessary.
Workflow execution account
You can configure the execution account to be used at the workflow template level. The execution account lets you map authorizations to the workflow directly, irrespective of the Adobe Campaign operator starting the execution. By default, every workflow is executed with the rights of the operator who started it.
To map an execution account to a workflow, go to the list of workflow templates and right-click on the template linked to the workflow. Choose Action > Change execution account… then select the account to be used.