A visual look at what to consider when designing secure chips for IoT from ARM

1. Right-sized Security for IoT
Mike Eftimakis
IoT Product Manager, ARM
Case study – Tape-out a secure IoT chip in 3 months!
Selecting the “Right Size” for IoT security
HW Attacks
 Physical access to device – JTAG, Bus, IO Pins
 Well resourced and funded
 Time, money & equipmentSoftware Attacks
 Buffer overflows
 Interrupts
 Malware
Communication Attacks
 Man In The Middle
 Weak RNG
 Code vulnerabilities
Cost/Effort
To Attack
Cost/Effort to
Secure
Non scalable
IoT
Subsystem
for Cortex-M
eFlash
Interconnect
Flash Cache
eFlash
Flash Cntl
SRAM
Controller
APB
PeripheralsSRAMSRAMSRAMSRAM
ProcessorCortex-M
CoreSightSoC
mbed OS
Device Drivers
Application
Beetle
Test chip
Power
Management
TRNG
APB
Bridge
Cordio
Radio
ARM® mbed™ OS
(including mbedTLS, mbed uVisor)
TRNG
(from ARM TrustZone® CryptoCell)
ARM IoT Subsystem
for Cortex®-M
ARM Cortex-M3
ARM Cordio® Radio
 Device management
 Support for bootstrapping /
provisioning / refurbishing /
decommissioning
 Behaviour monitoring
 Device integrity
 Protect from untrusted software
 Allow recovery from attack
 Asset protection
 Prevent access to certain
resources
 Data Security
 Keep data confidential
 Prevent data alteration
 Physical Security
 Anti-tampering protection
 Future-proofing
 Keep firmware up-to-date
Device security
Communications security
Lifecycle security
 Link encryption
 Prevent eavesdroppers to listen
 Authentication
 Guarantee identity of endpoint / server
 Anonymity/Confidentiality
 Keep identity unknown to eavesdroppers
 Prevent traceability
Implement
OMA LWM2M
ImplementTLS
Root of Trust +
Chain ofTrust
HW backed
partitioning
(MPU)
Implement Dual
Flash bank +
Secure FoTA
HW backed
partitioning
(MPU)
Partition SW
Resource
IoT
node Cloud
Disrupt device
Observe / corrupt
data
Access protected
network
Damage cost = value of lost data
or side information (presence…)
Damage cost = value of lost cloud data
or value of the network infrastructure
Damage cost = value of disabled node
or value of lost node data
× Scale
of network!!!
Estimate threats for your application
“Security” has different meanings
Device management
Support for bootstrapping / provisioning /
refurbishing / decommissioning
Behaviour monitoring
Device integrity
Protect from untrusted software
Allow recovery from attack
Asset protection
Prevent access to certain
resources
Data Security
Keep data confidential
Prevent data alteration
Physical Security
Anti-tampering protection
Future-proofing
Keep firmware up-to-date
Device security
Communications security
Lifecycle security
Link encryption
Prevent eavesdroppers to listen
Authentication
Guarantee identity of endpoint / server
Anonymity/Confidentiality
Keep identity unknown to eavesdroppers
Prevent traceability
Select the
“right-sized” security!
 Security is expensive
 Need to understand the threats
 Use threat model adapted to IoT