Reuters. North Korea says successfully conducts first H-bomb test.

This is total nonsense. All successful hydrogen bombs are derivative of one element: the Teller-Ulam design, which is a method of coupling the energy of a fission “bomb” to a mass of heavy hydrogen (deuterium), so as to initiate nuclear fusion, the “energy of the sun.” No alternative to this design element exists.

It’s very hard to do. In building a nuclear weapon, there are intellectual levels. At one level is what is commonly known as “technology.” For example, the machining of plutonium, which is mechanically unstable, switching spontaneously between different allotropes, is difficult. Construction of a power supply to detonate an implosion array is also difficult. But the most difficult part of these achievements is the first time. The construction of a fission weapon is, as proliferation has shown, a replicable achievement.

The higher level, the stuff of genius, is  mathematical physics. The design of a nuclear weapon is not simply the shape of a gadget sitting on a shelf. It is the evolution of the device under phenomenal dynamical forces over several hundred microseconds. With a hydrogen bomb, the problem of intellect becomes acute. For the H-bomb, we had Edward Teller and Stanislaw Ulam. The Russians had Andrei Sakharov, and the public knowledge that it could be done. The subsequent independent development by the Britain, France, and China may be considered independent, but people talk.

Perhaps North Korean scientists will hear some talk. But the proof is in the pudding. In this case, the stretching of the truth most likely takes the form of putting some deuterium  and tritium gas, or solid compound of, in the center of the plutonium pit. This enhances the performance of a fission pit, reducing the critical mass, facilitating miniaturization. This is  a boosted fission weapon.