They SHOULD be dry (not dead dry). - Longer preservation
they should be in the dark. - Longer preservation
they should be kept cold (fridge). - longer preservation
So in short keep it in the fridge. If you need to store them longer (year) - freezer but that could also have an impact on germination rate. Not too much movement + climate change.
Probably some seeds will germinate in a decade some not after one month ;-)