My guess about the Israeli/Russian SAM access code bit, was someone's trying to save face (or their ass).
All of Russia's customers are Israel's enemies, giving out access codes is bad for business
Primary radars don't have "secret codes" that allow a target to turn them on or off. Secondary radars (not really radars at all, but beacon tracking systems such as IFF) might fit such a description. No SAM I have ever heard of uses a secondary radar to track the non-cooperative target, they use primary radar for skin track of a target, although they may use a beacon system associated with the missile after they have fired it.
Monostatic primary (skin track) radar works as a stand alone system. It emits a pulse of energy and looks for the return of that energy from a reflective target. While radar pulses may be coded for a variety of reasons the "code" does not make or stop the pulse from reflecting. So "having the code" would not make your aircraft undetectable or make the radar not see a skin return, I have never seen a "code" that a target could have that would turn off the radars ability to see it. To have such a feature, no matter how closely guarded, would be asking to have it exploited.
The article says "the Russians gave Israel the secret code of the Russian radar in Iran". If there is any truth to that at all, even the slightest sliver, it would probably be the codes to the IFF, Identification Friend or Foe, system. I see no reason the Russians would do such a thing. Also, why would the Russians even have that code? The key probably changes on a regular cycle, and there is no need for the Russians to be involved in such changes, the Iranians themselves would most likely handle that aspect of things. While the Russians may have supplied a lot of the IFF systems in Iran (or may not, I don't know) why would they be involved in day-to-day code changes?
And even if the Israelis had the IFF codes, IFF does not prevent primary radars (skin tracking radars, essentially all SAMs) from seeing targets, it only allows a primary radar to correlate a skin tracked target to a known, or unknown, aircraft.
And to top it all off, while Russia has provided a lot of the radar systems in Iran, Iran has also made great claims of indigenously developed systems, including HF and VHF radars (Sepehr, Nazir, and BSR-1, among others) specifically optimized to defeat the current state of LO technology. Even assuming disabling "codes" existed, why would Russian even have access to the "codes" to such radars?
Don't get me wrong, if the Israelis had the IFF codes that would be a huge plus for them. Enter the airspace from another direction, get pinged, get IDed as a friendly, and go about your business. If no one on the ground questioned why that aircraft was doing what it was then that is just too bad. But why would the Russians need to give the Israelis such a code?
Surely the Israelis might have heard of SIGINT/ELINT/MASINT on their own? (Just in case someone missed that, that last sentence was sarcasm, take a look at the state of Israeli EW.)
And just for the record, I think any mention of Russians supplying "codes" is bunk. I also doubt the Israelis diddled with the IFF, although that is possible. It is far better to remain undetected than to advertise your position by spoofing someone elses IFF.
T!