The Codes is the English title for Szyfry, a Polish film released in 1966, directed by Wojciech Has.
Tadeusz returns to Krakw to discover that Maciek is alive, his wife may have been a partisan, and that his son may have turned his own mother in to the authorities.During Macieks struggle to understand his parents history, questions arise concerning collaboration with the Gestapo and retribution by the Home Army. Has pictures the mystical lost boy in a dark fairytale forest, full of the wars ghosts and wholesale executions. The hypnotic quality of these excursions foreshadows the mesmerizing passages of Has later film, The HourGlass Sanatorium. ........
Source: Wikipedia