*Существует версия согласно которой конструкторская документация и, возможно, некоторые компоненты проекта были переданы КНДР. Якобы на базе проекта Р-18 была разработана ракета Nodong. Нами данная информация не подтверждается, но теоретически возможно, что КНДР получила разработчиков - носителей информации из СКБ-385 (г.Миасс), выезд большой группы которых в КНДР был пресечен в 1990-х годы. При создании ракет Nodong возможно были так же использованы специалисты СКБ-385 т.к. у ракеты прослеживаются общие черты с ракетами СКБ-385 1960-х годов выпуска.
Source: http://military.tomsk.ru/blog/index-359.html

Meanwhile at first by Novosti Kosmonavtiki published sensational photos of the Chinese first stage engine YF-2 from the DF-3 missile. It is now confirmed that four single engines are combined with its own turbopumps. The shape of the chambers and the nozzles are more similar to the smaller Scud-B engine than to the Nodong/R-18 engine. The Nodong engine has greater similarity to the Soviet four-chamber engine Isayev S2.1100 (Burya booster). In addition however clear differences between all engines are to be determined. In any case, this engine YF-2 is a creation of Isayev's design bureau. All the details are typical.

It is reported by KB Makeyev that the development of an operational tactical missile R-18 was stopped in December 1958 in the preliminary planning stage. It should be a  R-17 similar missile with a longer range. Was the development later continued ?
An interesting reference for the origin of the Nodong  is a  drawing for the manufacture of an engine, whose measurements and outlines equal the Nodong engine. It is possible, that this engine belongs to an unknown Soviet  missile R-18, which exactly corresponds to the Nodong missile. Possibly the engine was constructed for the use of UDMH as fuel, as for the Isayev engine YF-2. These missile was not taken over however in the rocket arsenal of the Soviets, probably however exports to North Korea. This is realistic because Cyrillic letters were seen on a Shahab-3 (Nodong) missile.

A single Nodong engine has a thrust of approximately 284 kN (s.l.). That can calculated become with the kind of propellant, the quantity of ~11.151 kg and the burning time of 95 sec (Taepo-Dong-1 launch).
Pakistani Ghauri missile have a quantity of 12.912 tonnes propellant. It is calculated a burning time of 110 sec. The Iranian Shahab-3M (syn. Ghadr-I) has an equal dimension. The new Iranian Ghadr-II missile is once more longer. It is used as first stage for the Safir IRILV. It is based on a Nodong++ missile, which was used probably as the first stage of the unknown North-Korean  Unha-1 SLV.

A statement to the Nodong missile by Schmucker Technologie, Munich, Germany , 2010
The Missile Show. Prof. Dr.-Ing. habil. Robert H. Schmucker & Dr.-Ing. Markus Schiller

“In 1993, four missiles were launched in the DPRK. The exact missile types are still not known for sure, but one is said to have been the first appearance of a new rocket that would soon play a central role in the 3rd World arsenals. This missile, designated Nodong by the West, looks like an upscaled derivative of the Scud. Main diameter is roughly 1.3 m compared to Scud’s 0.88 m, and the whole system is accordingly larger, heavier and offers more per10 formance.
In the same year, a number of Russian missile experts from the Makeev design bureau tried to emigrate to North Korea. This was prohibited by Russian authorities, but it is not known if they found another way to the DPRK.
Since 1998, Nodong can be found in Pakistan by the name of Ghauri, and in Iran as Shahab 3, where it first appeared at a military exhibition, littered with numerous Cyrillic markings.
Lucky chance revealed the true origin of the engine. In 2001, a Russian textbook was published in context with a training course for rocket production in Iran. This book contains the drawing of a manufacturing device for rocket engines. The decisive figures of the according engine – nozzle and throat diameter – perfectly match those of the Nodong engine, as photos of the Iranian Shahab 3 engine clearly show. It is a Soviet-Russian engine, and the characteristic details of the Isaev design bureau are clearly visible.
Engineering details and technical data of Nodong are strikingly characteristic for Soviet missile concepts of the late 1950s. At that time, competing design bureaus proposed, pre-developed and tested dozens of different missiles that never reached the state of serial production and disappeared in the fog of history. To give an example of the scale of Soviet rocket efforts at that time: Isaev alone developed more than a hundred different engines, of which several dozens entered serial production.
Thus, it seems clear that Nodong is an early Soviet missile, perhaps the little known R-18 (or R-19).”

Quote, 2012, March 15: “The Scud-engine (S5.2) and the Nodong-engine were both designed at Isayev’s OKB-2. The Nodong is not something North Korea developed by "scaling up" the Scud engine. The book: I know both of the authors of this book which contains technical descriptions for the manufacture of the Nodong engine; they both have seen the "Nodong" engine while working in Iran during the late-1990s. They have stated to me that what they saw was an Isayev engine, produced in Russia.”
Source: www.iranmilitaryforum.net/space-technology-and-news/
 

 UDMH/AK-27

 Isayev n.n. (1)