Theoretically, democracy thrives best when in openness. However, in real life, democracy can only thrive in secrecy. Democratic countries are more open to external threats. To successfully fight and defeat such threats, democracies ought to operate in secrecy in order to keep their enemies in the dark and minimize the risk. Democratic countries also face more internal threats. For internal negotiations to succeed, they must be kept away from the public.
I personally think that democracy must maintain secrecy if it has to survive all external and internal threats and thrive with minimal loss of blood and wealth.