Welcome into web compatibility world - lot of companies do nice buck out of its quick evolution. And this is very, very good thing for you too if you play it we

Welcome into web compatibility world - lot of companies do nice buck out of its quick evolution. And this is very, very good thing for you too if you play it well. For internal use the answer is self-signed certificate. However I wouldn't count on web browser based software compatibility to last even 10 years. I think browser vendors at some point will decide to ditch <512-bit certs or some encryption scheme and one needs to make a cert/server upgrade. Some option may be Firefox ESR [0] requirement to ease an adoption. Moreover browser is UI part of your solution and you need to define some requirements - this should be all right for well administrated environments. If the user for any reason upgrades/changes the browser but not your device then this is user introduced incompatibility. Your EULA should cover that. Also you should send notifications or just show some message in device panel to your customers that they need and upgrade if they want to use given browser past version X. Customers need to learn that web means edge tech and that needs frequent upgrades. Their isolated internal network of the past e.g based on WiFi WEP would be practically a network open to bad actors today. [0] https://www.mozilla.org/en-US/firefox/organizations/ https://www.mozilla.org/en-US/firefox/organizations/