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- [Man] LoRA or LoRA WAN networks operate

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in the 868 megahertz and
900 megahertz ISM bands.

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The data rates can be from
0.3 kilobits per second

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to 50 kilobits per second

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over several kilometers.

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And that's one of the main differences

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between LoRA and the all
the other technologies

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that we cover related
to IoT communications.

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Now LoRA supports several device types

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including low power sensors
that collect data in the field.

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LoRA devices communicate
with a LoRA gateway

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and that gateway sends
data to a network server.

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And on to application, you know

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servers accessible by the
administrators of LoRA devices.

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Let's go over the LoRA one security model.

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LoRA specifies two types
of symmetric session keys.

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These are unique to each LoRA device.

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The Network Session Key

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for networks layer
messaging manages integrity

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from you know, basically the LoRA device

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to the LoRA network server.

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And also the App Session Key is, you know

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the other key that is actually used

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for application layer
end to end encryption

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from the LoRA device to
the application server.

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Now, there are two ways that devices

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can join the network, right?

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The first is over the
air activation or OTAA

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and the basically the LoRA
device and the network server

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our first provision with 128 bit AppKey.

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And then when the LoRA
device is first powered on,

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it will send a joint request
to the LoRA network server.

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The AppKey is used to create
a Message Integrity Code

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or a MIC along with information including

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the device ID and the device nonce.

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The server checks the MIC with the AppKey.

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And then after validation,

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the network server generates
two new 128 bit key

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you know, device keys, the App Session Key

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or the App S Key and
the Network Session Key

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which is also called the NWKS key, right?

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Now, the keys are sent
back to the LoRA device

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using the AppKey as the
encryption key itself, right?

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Then the LoRA device decrypt
and install the session keys.

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The other method is the activation

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by personalization or ABP.

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Basically the LoRA device is
provisioned with session keys

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you know, the Network Session
Key and the App Session Key

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and this can be done
at manufacturing time.

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Now this LoRA devices
can be in communicating

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with the LoRA network
server using those keys.

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Now, one to highlight is that
man in the middle of attacks

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are pretty unlikely
because of the uniqueness

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of these session keys.

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This is somewhat stronger
than the other IT protocols

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that we cover earlier in the course.

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There are other potential
threats, although for example

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the ABP key provisioning.

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So the activation by
personalization creates session keys

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for the LoRA device possibly
at manufacturing, right?

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So these session keys have to
be injected into the device

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and securely transported
to the LoRA network server.

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So again, there's a of
course the potential

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of supply chain attacks
in that case, right?

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Now there's hardware
security modules or HSMs

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at the manufacturing
site that can actually

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be implemented to be
the best way to do this.

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You know, these key management so that

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the keys are not exposed
during the device programming.

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So the LoRA device programming.

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Now, another thing is that

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during the over the
air activation or OTAA,

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that process actually
uses a secure methodology

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for generating session keys.

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However, the app key must be
provisioning a secure manner

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and securely transported
to the network server.

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And this could be done over HTTPS

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in a secure web client server model.

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However, if the implementer or
the vendor does not configure

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or does not enable
HTTPS or TLS by default,

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there will definitely be an opportunity

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for you as an attacker
to actually eavesdrop.

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But that's of course, very unlikely.

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You know, there's a lot of
guidance by the LoRA community

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that actually highlights this

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you know, in many different
type of documentation, right?

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So, but again, the
possibility is still there.

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Now, LoRA device key storage
is another consideration

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that you know, may also
have to take care, you know,

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as an attacker you may
actually have access

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to the device keys, the AppKey,
the Networks Session Key

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and the App Session Key,
and you can easily spoof

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and node if you actually have
those in your possession.

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So therefore that's why
these keys definitely

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should be stored securely not
only within an environment

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but within those devices themselves.

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Right? So encryption
at rest is actually one

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of the main things that,
you know, implementers

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should pay attention to.

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Now, well known sided channel attacks

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can also be used to recover these keys

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from memory that is
actually not accessible

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via software means, right?

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A mitigation for that is
actually smart car chips.

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And these are secure elements
that have been designed

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for side channel protections.

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Now, another consideration is
the Client-Side Key Storage.

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Depending on the application
server architecture,

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the client could be responsible
for the secure key storage

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of all those keys zero.

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So the App key, the Network Section Key

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and the App Session Key.

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So to mitigate the threat of, you know,

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this type of exposure, all device keys

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are encrypted under a master key.

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So they're not exposed
whenever in use, right?

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Clients and implementers can
also employ a USB smart key

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to protect key material in
a physical device, right?

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Now another consideration is also

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the LoRA network server key storage.

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And again, it's actually
the network server

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is used to generate the device keys

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for all the LoRA devices.

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So if it's actually compromised, of course

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you actually have the keys to the kingdom.

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In that case, all device
keys should be encrypted

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under the master keys to
actually mitigate threats

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of exposure.

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So in summary, the main security risk

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with LoRA is the key
life cycle management.

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This includes the session
key, the generation, you know

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that session key, the
storage and the transport.