One German cryptanalyst stated that the Typex was more secure than the Enigma since it had seven rotors, therefore no major effort was made to crack Typex messages as they believed that even the Enigma's messages were unbreakable. Although the Typex has been attributed as having good security, the historic record is much less clear. There was an ongoing investigation into Typex security that arose out of German POWs in North Africa claiming that Typex traffic was decipherable. A brief excerpt from the report  TOP SECRET U [ZIP/SAC/G.34] THE POSSIBLE EXPLOITATION OF TYPEX BY THE GERMAN SIGINT SERVICES  The following is a summary of information so far received on German attempts to break into the British Typex machine, based on P/W interrogations carried out during and subsequent to the war. It is divided into (a) the North African interrogations, (b) information gathered after the end of the war, and (c) an attempt to sum up the evidence for and against the possibility of German successes." Apart from an unconfirmed report from an agent in France on 19/7/42 to the effect that the GAF were using two British machines captured at DUNKIRK for passing their own traffic between BERLIN and GOLDAP, our evidence during the war was based on reports that OKH was exploiting Typex material left behind in TOBRUK in 1942. Typex machines continued in use long after World War II. The New Zealand military used TypeX machines until the early 1970s, disposing of its last machine in about 1973. All the versions of the Typex had advantages over the German military versions of the Enigma machine. The German equivalent teleprinter machines in World War II (used by higher-level but not field units) were the Lorenz SZ 40/42 and Siemens and Halske T52 using Fish cyphers.