The Google translation is actually very close, aside from German sentence structure being what it is and mis-matching some of hte objects and modifiers. Correcting it for sense should be more like:
"The archive photograph shows the Shahab-3 missile test in November 2006. Photo: AP
According to information from the Süddeutsche Zeitung (South German News[paper]), Iran has developed a design for an advanced nuclear warhead with the help of a scientist from a former Soviet nuclear weapons laboratory.
Western intelligence agencies and diplomats confirmed this information from a paper which was in the possession of International Atomic Energy Agency inspectors in Vienna to that effect, and the Süddeutsche Zeitung has seen the paper. According to the inspectors, the warhead would work.
It utilizes a so-called Two-Point Implosion System. Unlike older models, it needs only two special warhead detonators, called Exploding Bridgewires (EBWs).
By this means, a reduction of the diameter is facilitated, to the extent that it would be small enough to be loaded into and fired in an IRBM such as the Shahab-3. Iran has admitted to the IAEA that it has made experiments for the synchronous firing of several EBWs."
ETA - Note that it is talking about Iran having a apparently-viable design in hand, not an actual or prototype weapon. There are a lot of pitfalls between the two, the development discussed here would make a functional weapon more easily delivered, but the 'Hard part' of nuclear weapons design actually lies in another direction, not just the explosives engineering for symmetrical detonation of the implosion charge.