Hi everyone. I’m very new to SmartThings so I apologize for the “noob” question.
I was able to successfully connect my evalogik zwave outdoor plug to my hub, however I receive the following error message:
“Your device has been connected, but it isn’t using the highest level of security. For more security, exclude the device and try it again.”
After doing some googling, it looks like its failing to connect via S2 security. Under device status I see the following error " ZWAVE_S2_FAILED"
I’ve tried excluding the device and connecting it multiple times to no avail. The manual mentions a command class list which shows a command for class security 2, so I’m assuming S2 security is compatible with this device. Do I need to use a device handler to enable this feature?
From what I understand SmartThings did not offer any S2 support until a few months ago. Is this correct?
How concerned should I be with the lack of S2 security? I guess because the word “security” is involved, I’m a little worried about increasing the chances of unauthorized access. I’m not sure what S2 security offers vs S0 making it harder to truly understand everything.
Long story short should I be worried? And is there a way to fix this?
Which model hub do you have?
Honestly, Not much unless you are in very specific circumstances and expect to be an individual target. In which case you probably wouldn’t be using smartthings anyway. 
S2 Allowed Z wave to start being used for UL listed security systems, like the one from ring, and that’s a good thing. But it’s unlikely that anybody is going to try and hack your light switches or pocket sockets, or that they could do much damage if they did.
For most typical homeowners, S2 security is the equivalent of getting a really good door lock on a door that’s next to an unbarred window. It’s not a bad thing, but it’s unlikely that the lock being that good is really going to make a practical difference anyway. Most non-targeted attacks are going to come via Wi-Fi, not Z wave.
On the other hand, if you have a malicious ex with very strong tech skills Who knows you have a Z wave home automation system, you might care more.
Security is one of those areas where different people can have very different circumstances, and therefore very different requirements. So it’s just a question you have to decide for yourself as far as how much peace of mind you require for your set up. 
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Thanks for the reply! I have a 3rd generation hub. I double checked and I’m up to date with the firmware.
And thanks for your explanation. From the way you describe things, it looks like I don’t have much to worry about considering this is only an outdoor switch. All the same, it would be nice to fix the problem anyways. Part of me feels there could be an issue with the actual plug itself. Maybe I should exchange it for another.
Could I ask a follow-up question? Do zigbee products also use S2 security? Or do they have their own protocol?
Thanks again.
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Zigbee devices have their own security protocol. “S2” is just the fancy marketing name that the Z wave alliance gave to their upgraded level of security. It’s not a third-party standard. 
As far as your current Z wave device, try pairing it close to the hub and see if that makes a difference.
I’d also try excluding it and then choosing the z-wave brand from the list to pair it. I have a theory that not all S2 devices are flagged as such in the app. Although maybe it shouldn’t matter per z-wave certification? Anyway, might be worth the try.
Based on the protocol, the device should request an S2 pairing at the time that it joins, unless there’s a parameter setting that affects that. That is, the default is that each device should try to join at its highest possible security level, again, unless there’s a parameter to change that. But I don’t know what smartthings does with it.
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