You also need a fully open and transparent government, any information being classified top secret or anything of the sort means you cannot have a democracy. No secrets can be allowed, ever. And really the only way to reasonably guarantee stuff like that is to make officials surrender all privacy related rights for life, just permanent publicly open insight into every aspect of your life, past, present, and future if you want to pursue office. I'd argue for attaching 24/7 live streamed cameras to them during their time in office as well. Obviously this would only currently work for rich countries with obscene military expenditures, like the US, but if the big guys were to do it then it would eventually be safe enough for the rest of them.