Sharashki - Stalin"s innovative project

Sharashki " - as the people called the subordinates of the NKVD of the USSR secret research and design bureaus, where prisoners and designers worked. It was always believed that the work of the "sharashki" was ineffective, and the working conditions in them were terrifying. However, the author, on the basis of many recently declassified documents about their activities, proves that this is not so. The paradox is that in the Stalin’s “sharashki "discoveries and inventions, more than thirty years of“ democracy ”in Russia was made.
Why was it possible, what were the advantages of “sharashki ", how experts lived and worked in them and what role did the NKVD employees played in the organization of the work of these prison and KB? About this and much more is described in this book