IoT SecurityHandbook

How Arm Is Helping to Secure a Trillion Connected Devices

As we increasingly integrate
more devices in our lives, thepotential effect of security
breaches is huge!

02How ARM Is Helping to Securea Trillion Connected Devices04- Understanding Potential Vulnerabilities

04- A Handy Starting Point

06- Layers and Lifecycles

07

How Can Arm Products andServices Help to Secure the IoT?

08

- A Foundational Approach08- Security Technology

08- Silicon Level Protection

09- Secure Software Development

09- Managing Secure Identity09- Connecting from Device to Cloud10- Mbed TLS

10- Pelion Device Management

10- Lowering the Barrier for Cellular Connectivity

11How Arm Is Helping to Secure a Trillion Connected Devices

Table ofContents

03

At Arm we place
importance on approaching
security from the ground
up. We achieve this by
not only considering
the protection you needto put in place, but also
your recovery from theconsequences of a breach.
To truly enable systems built on trust,security cannot be considered a separate
component, or as an afterthought to therest of a system. It must be embedded inevery element and process that exists inyour Internet of Things (IoT) deployment.
Companies who are creating IoT solutions
often find themselves navigating aHow Arm Is Helping to Secure a Trillion Connected Devices

How Arm Is Helping to Securea Trillion Connected Devices
technologies and processes – without
the in-house expertize required to help itmake sense. Arm has a vision for security,and to help make it a reality, we launcheda number of programs, services and IP
products, to help companies who needto deploy network-wide security as
part of their everyday business.
Understanding Potential Vulnerabilities
The first stage in designing security
is understanding the environment
surrounding a device or service, andwhat the potential threats could be.
Arm identifies four main categories ofpotential vulnerabilities: communication,
lifecycle, software and physical (alsoknown as silicon). The risk of each ofthese happening will largely depend on
your application, how it’s being used
and the potential value of your data.

complex landscape of security standards,

IoT security should be embeddedin every element and process of
your IoT deployment.

04

How Arm Is Helping to Secure a Trillion Connected Devices

To truly enable systems
built on trust, security
cannot be considereda separate component.

05

The Platform Security Architecture (PSA)

security design and provides a holistic

is the framework for securing a trillion

set of resources for the requirements

connected devices. Backed widely byanalysis, architecture and implementation

Arm’s partners and industry leaders,phases of device design. PSA Certified

it’s a four-stage process for making IoT

provides multi-level, independent testing

security easier and quicker to implement.

of IoT devices built on PSA principles.

PSA suggests common principles for

How Arm Is Helping to Secure a Trillion Connected Devices

A Handy Starting Point

Platform Security Architecture
A framework for securing a trillion connected devices

Analyze

Architect

Implement

Certify

Threat models &security analyses

Hardware & firmware
architect specifications

Firmware source code

Independently tested

Arm aims toIf you’re looking for help or advice fora more secure device. This will enable

demystify threat

analyzing vulnerabilities in a system oryou to make the right choices whenmodelling byproduct, the right place to start is withselecting counter-measures to protect

providing a variety

threat modelling. Threat Model andfrom vulnerabilities.

of examples that

Security Analyses (TMSA) documentation

you can download

is specifically designed to derive security

PSA is the start of a longer-term effort

for free.

requirements. If you’ve never consideredby Arm and the ecosystem to raise thethreat modelling before, this can seembar on IoT security. Whether you design

like a daunting process. Arm aims tochips, buy them, or deploy devices intodemystify threat modelling by providing

the field, PSA will provide a foundationala variety of examples that you cansecurity framework for future systems.

download for free, as part of thePlatform Security Architecture.
Once you’ve completed your threat
modelling, you will be equipped withall the information you need to specify

Access PSA threat models, architectural
specifications and other resources atwww.arm.com/psa-resources06

Security does not stop at the system-on-

Let’s consider a typical IoT deployment,chip (SoC) level or when a device rolls

which includes a hardware device

off the production line. Good security isrunning firmware, connected to a

implemented through layers of hardware

network and communicating with aand software, considering both theservice, commonly deployed in a private

individual device and complete systems

or public cloud. All the following aspects

in which it functions, including cloudmust be addressed, to assure security ofconnectivity, data analytics and control

the IoT system, and PSA helps define andcomponents. Mitigations need to beimplement these aspects, outlined below.

How Arm Is Helping to Secure a Trillion Connected DevicesLayers and Lifecycles

maintained against a constantly changing
landscape – as new threats emerge
and while devices are built, deployedand retired.

Usage Lifecycle of an IoT Device
1The device may contain sensitive data and must be protected from vulnerabilities(including both physical and remote software threats) to ensure data confidentiality,
trust and validity.

2To secure internet connectivity, a device must be provided with a unique identitywith keys and certificates that are used to attest and authenticate itself with backend
services. Additionally, they provide integrity and confidentiality of the end-to-end
communications and information exchanged. It’s also advantageous to have thecapability to remotely manage these security credentials, so that new trusted
networks and services can be used.

3Over time, vulnerabilities will be found in the device firmware, therefore, you willneed the ability to create and push new firmware updates to the device over-the-air.
When the firmware is updated, it’s important that the device can check that theupdate is from a valid source.

4Once the device reaches its end-of-life, or is passed to a new owner, it is importantto have the ability to erase all the sensitive data it contains and block its accessto previously-approved network applications.

07How Arm Is Helping to Secure a Trillion Connected Devices

How Can Arm Products andServices Help to Secure the IoT?
A Foundational Approach
Arm provides tailored solutions for

isolation in CPUs and systems, enabling

jump starting secure PSA ready SoC

a secure Root of Trust (RoT). The family

designs. Matched against the mainof TrustZone technologies is supported

IoT application classes (constrained,by any Arm Cortex-A and the latest

mainstream and rich), they map out theCortex-M23, Cortex-M33 and Cortex-

necessary hardware, software and tools

M35P processors. Whether it’s thefor each set of requirements. Security

smallest of microcontrollers or high-is taken into account from the system

performance applications processors,architecture definition. It is pre-built intodevelopers can achieve isolation to help

the subsystems, using the PSA principles

protect embedded and IoT devices fromand integrating security IP like firewalls,

software vulnerabilities.

Secure Enclave and TrustZone technology.
If you’re looking to protect against
Security Technology
Arm has a number of technologies andIP products for designers building a SoC
that requires an extra level of securityrobustness. These security technologies
target each type of threat.
Arm TrustZone technology has beenoffering foundational security sincecommunication and lifecycle
vulnerabilities, the Arm CryptoIsland

Arm TrustZone

and Arm CryptoCell families support

provides robust

Roots of Trust (RoT), security services,

hardware-enforced

lifecycle management, key management

software isola-and cryptographic acceleration. Thesetion in CPUs andcryptographic and security functions aresystems, enabling a

critical to countering a wide range of

secure root of trust.

security threats.

2004, and has a rich heritage in securing
mobile devices. Arm TrustZone provides
robust hardware-enforced software

08

Silicon vulnerabilities and physicalprogram a device, with support for

security threats are becoming more andover 6000 Arm-based microcontrollers.

more prevalent, due to the availability

This includes a number of open-sourceof tools and knowledge. To help counter

CMSIS packs, which provide reusable

this threat, Arm introduced an enhanced

code that works across different devices.

family of IP. The family includes the Arm

Arm MDK also offers support for

Cortex-M35P processor, which offers a

Trusted Firmware-M (a key componentrobust, high-performance processor withof the Platform Security Architecture)anti-tamper capabilities.

which allows you to create secure IoT

Physical security

software fast.

threats are

The family also includes enhanced

becoming more

IP from the Arm CryptoCell andWhen coding for security using

prevalent, due toArm CryptoIsland families offering

Armv8-M processors, developers canthe availability

protection against side-channel attacks.

easily reduce the attack surface exposureof tools andknowledge.

How Arm Is Helping to Secure a Trillion Connected Devices

Silicon Level Protection

by using CMSIS- ZONE with TrustZone
Secure Software Development
The reality of IoT will see over one
trillion connected devices all using
different hardware, with a variety ofdifferent standards and protocols.
This means that deploying secure
software will be both time-consuming
and challenging. How can we ensurethat software development is as easy
as possible? The challenges of coding,testing and maintaining highly secure
software are more easily tackled using
Arm software development tools.
The Arm Keil Microcontroller
Development Kit (Keil MDK) offers
everything a developer needs toand/or memory protection units (MPU).
CMSIS Zone simplifies Arm TrustZone forArmv8-M partitioning, offering a quicker
route to secure and non-secure domains.
In the event of code maintenanceafter a device has been deployed,developers can use our secure debug
capabilities that only allows verified
sources access to authorized secureareas for debug, using debug overfunctional interface and certificatebased authentication. Secure debug ismade possible using a combination ofArm security IP, Arm CoreSight SDC600 Secure Debug Channel and Arm
debug adapters.

09

How Arm Is Helping to Secure a Trillion Connected Devices

Managing Secure identity
Identity must be a key aspect of all IoT

building blocks you need to create,devices and it is one of the fundamental

deploy and manage devices securely,

PSA security principles. Arm Kigen family

from end-to-end.

offers SIM grade identity for cellular IoT
devices. This allows mobile carriers toreply, host and assure the device’s unique
identity and its associated network
attestation credentials.
The Arm Kigen product family offers thelowest footprint and standards-based
secure Kigen SIM OS for devices. It alsooffers a security-accredited Remote SIM
Provisioning service to manage SIMs
through the lifecycle of these devices.
The flexibility of implementing Kigen SIM

Mbed TLS
IoT devices usually contain sensitive
application data, and device keys areused to communicate with the cloudservices or to verify firmware signaturewhen updated over-the-air. The Mbed
TLS library provides a set of software
cryptographic components that allow
developers to secure communications.
Pelion Device Management

OS in different form factors (SIM, eSIM,Pelion Device Management securesiSIM) will unlock the potential of cellular

all stages of the device lifecycle, fromIoT across 2/3/4/5G, NB-IoT, Cat-M andmanufacturing through to end-of-life.

others enabling scale and security.

It offers a service specifically designed
for fail-safe, secure delivery of firmware

Connecting from Device to Cloud
From cryptographic libraries on thedevice, through to secure firmware
updates in the cloud, the Arm Pelion
IoT Platform offers the security-specificover-the-air (FOTA), which is the only
efficient way to distribute and installrequired software. Pelion Device
Management also solves anothercritical challenge of IoT security: strict
management around who can accessdevices and data.

10Cellular Connectivity
Connecting a cellular IoT device comes

Kigen iSIM these barriers are removed

at a cost, such as complex logisticalor lowered by removing the additional

steps, the hardware Bill of Materials

steps that are required today. Kigen iSIMand assembly, as well as physical space.

leverages PSA principles, CryptoIsland

It is a struggle to justify adding cellularand Kigen SIM OS to enable remotelyconnectivity with current technology,

provision SIMs, within the existing silicon

especially for (but not limited to) small-footprint. This is supported by secure

footprint, low-cost devices, such as

hosting by a certified service, such as thesensors. With the introduction of Arm

Kigen Remote SIM Provisioning service.

How Arm Is Helping to Secure a Trillion Connected Devices

Lowering the Barrier for

Matching the Vulnerability with the Right Mitigation
To enable the internet of things to growfor each to enable the design

to its full potential, security needs toof secure devices.

be considered from initial design withTo discover more about the Arm

all vulnerabilities being considered fromsecurity solution, visit arm.com/

the start. Arm identified four types ofproducts/security-on-arm.

vulnerability with specific mitigations

PSA Analysis Stage

Assess the potential vulnerabilities
Physical	(including non-invasiveand invasive)

Communication	(including man-in-themiddle, weak RNG,
code vulnerabilitiesand data managementvulnerabilities)

SoftwarePhysical mitigation

Software mitigation

Arm SecurCore,
Arm Cortex-M35P,
CryptoCell-312P,
CryptoIsland-300P

Arm TrustZone, CMSIS-ZONE,
Arm Keil MDK, Arm processors
with TrustZone support,
Mbed OS and Mbed Linux

Communication
mitigation

Lifecycle mitigation

Arm CryptoCell & CryptoIsland,
Arm Pelion IoT Platform,
Arm Pelion Connectivity
Management,
Arm Kigen

Arm CryptoCell & CryptoIsland,
Arm CoreSight SDC-600,
Arm Pelion Device
Management,
Arm Kigen	(including buffer
overflows, interrupts
and malware)

Lifecycle	(including code
downgrade,ownership changesand unauthorized
overproduction,
debug attacks)

11About Arm
Arm is at the heart of the world’s most advanced digitalproducts. Our technology enables the creation of new markets
and the transformation of industries and society. We design
scalable, energy-efficient processors and related technologies
in applications ranging from sensors to servers, including
smartphones, laptops, enterprise infrastructure, embedded
and the IoT.
Visit www.arm.com