2.0 Discussion: Units, sensor types and protocol

[daulagari]

what benefit is there from encryption vs signing in the MySensors case?

If you have a lock or door sensor do you want others to know when it is opened or closed?

Signing is quite expensive if you look at additional payload size, you need a big counter to prevent replay and a big MAC to prevent attacks. I think that when encrypting things you can do it with the same additional payload and maybe even a less.

[Anticimex]

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[daulagari]

Yes, signing, when properly done, is for sure a good begin.

How many bytes are you using for the truncated MAC and nonce?

The AES block size is 128 bytes, so 16 bytes so I do not see why that would not fit.

Encryption is already some kind of authentication is a sense that if you can successfully decode the message you can be sure that the other side knows the shared secret, just like in the cause of your SHA25-HMAC.

[daulagari]

Would be good to move the last five message into a separate thread...

[Anticimex]

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[Anticimex]

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[hek]

I'm afraid I can only fork a topic int two threads. Haven't found a way to move posts to another thread/topic.

[Anticimex]

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[Anticimex]

@tekka Please see the discussion on security.

[lunarok]

Hi,

A new wish. Possible to have the network gateway listening for nodes also on the ethernet network. Looking for ethernet nodes inside the electric panel. No RF, no security break :)

[axillent]

A support for multi-gateway setup is needed. Currently it is required to hardcode radio-channel or base-address for different segments-different gateways

[marceloaqno]

There is a solution for multi-gateway that I'm working to port it to the development branch which could use the same radio channel and also to have sensors at gateway node.

[axillent]

@celonunes what kind of a solution it will be?
will it be possible to route messages between nodes managed by different gateways?

[marceloaqno]

Gateway become normal node, with an id(1-254), like a repeater. Address 0 become like a virtual address which is used when a node wants to send a message to the controller.
This solution will give more redundancy to the network but the same limitations apply, like the max of 254 per network.

[marceloaqno]

In the case raised by @lunarok, I'm not sure it will fit.

[axillent]

@celonunes said:

Gateway become normal node, with an id(1-254), like a repeater. Address 0 become like a virtual address which is used when a node wants to send a message to the controller.
This solution will give more redundancy to the network but the same limitations apply, like the max of 254 per network.

OK. But how this will prevent conflicts on the air between nodes connected to different gateways and having same radio channel and BASE_ADDRESS?

[marceloaqno]

Each node will continue to have a unique id in the network.
The controller would have additional work to map nodes to their proper gateway, and this could make the whole idea into something impracticable depending on the controller software.

[axillent]

@celonunes will you keep a limit 8 bit for ID?

currently with multi-gateway setup I have N * 255 address space, where N is a number of gateways

[marceloaqno]

@axillent said:

@celonunes will you keep a limit 8 bit for ID?

currently with multi-gateway setup I have N * 255 address space, where N is a number of gateways

Yes.
Your solution seems interesting, do you have some published code of it?

[axillent]

@celonunes it is not my solution) it is a way of using 1.4.1 with multiple gateways