It looks like Quartus Prime Pro supports IEEE encrypted verilog files but no Stratix devices and only Arria 10 and Quartus Prime supports most devices but no IEEE encryption?

[Kenny_Tan]

Which is correct, for std version, use amplic tools for encryption. 10. Q: How do I purchase a license with netlist encryption capabilities? A. Please contact your local sales for more purchase information. https://www.intel.com/content/www/us/en/programmable/downloads/download/licensing/q-and-a.html?wapkw=license+faq+altera