a) Iran send periodic letters as updates to the IAEA
b) The IAEA confirm the reported numbers through on-the-ground inspections.
The reason why Iran had to eventually confirm production problems is because the IAEA was reporting centrifuges being replaced and production numbers steadily declining to a halt.
The best report that ties all this together with Stuxnet is this one:
Comments
The IAEA report numbers are from two sources:
a) Iran send periodic letters as updates to the IAEA b) The IAEA confirm the reported numbers through on-the-ground inspections.
The reason why Iran had to eventually confirm production problems is because the IAEA was reporting centrifuges being replaced and production numbers steadily declining to a halt.
The best report that ties all this together with Stuxnet is this one:
http://isis-online.org/isis-reports/detail/did-stuxnet-take-...