BerlinWhen Siegfried Wittenburg first sat down to read the file compiled on him by the Stasi, East Germany’s secret police, he wasn’t sure what to expect. It was 1999, a decade after the fall of the Berlin Wall and the reunification of Germany. Wittenburg, 68, a photographer and former East German citizen, had spent a decade chronicling the regime. Among the images he captured were scenes of poverty, scarcity, and protest—things the East German government didn’t want seen at the time, leading them to censor some of Wittenburg’s photos at his exhibitions in the 1980s. Understandably, he was curious—and apprehensive—about the information his file might contain.

“I read it like a crime novel,” he says.

Wittenburg is one of the