The security tended to get tighter and tighter as time went by and more... "permeations" were discovered. So I expect security around the iron curtain in the '6

The security tended to get tighter and tighter as time went by and more... "permeations" were discovered. So I expect security around the iron curtain in the '60s was a bit more lax than in the '80s. If the Berlin wall is any example, it was.