Soft Signing vs. the hardware ATSHA

[Anticimex]

@NeverDie What sort of capability?
We are completely rethinking security for v3, and it will be a cross-device compatible format. However, atmega328p is too resource limited to be able to handle this in a good way, so we will not support that particular chip-set. The legacy signing options will remain for those devices.

[ThetaDev]

So what would be the microcontroller of choice for MySensors V3?

Using an ESP or NRF5 would be useless if you dont need WIFI or bluetooth (which isnt much use for home automation anyway, because bluetooth has a low range and wifi is a power hog).

Maybe the new 32bit ARM stuff?

[Anticimex]

@ThetaDev There is no recommended one, since it is totally up to you and your specific needs. What we aim for from a security point of view (and this thread is dealing with that, and not general v3 discussions) is a solution that is device independent (to some extent, it does put requirements on memory and performance, hence the support for atmega328p is dropped from this new security feature).
It will be HW independent in the sense that it won't support any specific security devices, like the ATSHA. It will be a purely software implemented feature. It may leverage chipset features, such as RNGs or HW accelerated calculators though.

[tbowmo]

@ThetaDev

NRF5 is not only bluetooth.. It can also be used with the "old" nrf24 protocol.

[mfalkvidd]

And it has 8x ram and 8x flash compared to atmega328

[Anticimex]

And if it is still undesirable there is always the samd which the SenseBender gateway is based on. Then you get the same freedom of choice as with a atmega since the radio is not built in.

[NeverDie]

@Anticimex said in Soft Signing vs. the hardware ATSHA:

Then you get the same freedom of choice

Actually you still have freedom of choice with the nRF5. You can use its mpu to control other radios, just as you would with an atmega. You could either ignore its existing radio, or you could have a node with two different kinds of radios (i.e. built-in plus add-on). That's the beauty of it. You can learn just one mpu and be done.

[Anticimex]

@NeverDie yes of course. Just seem a bit excessive to drag in a complicated chip if you don't intend to use all of it. Especially for battery powered applications.
But from a security point of view (again, which is what this thread is all about) it does not matter what chip you stick to. But if you want to use the "next level" security, don't expect it to support atmga328p.

[NeverDie]

@Anticimex So, to sum it up, will the "next level" be doing all the security inside a more more advanced mpu, or do you envision it will still involve the use of external chips, like the ATSHA chip or similar?

[Anticimex]

@NeverDie like I said above, it will be a software based solution, without dependencies to external chips. It may still leverage chipset specific features such as RNGs and crypto accelerators.