NXP Semiconductors EdgeLock A5000, Application Note

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NXP Semiconductors
AN13500
EdgeLock A5000 Secure Authenticator for electronic anti-counterfeit protection using device-to-device
authentication
1 Device-to-device authentication
The IoT environment increases the exposure of high value components to new
security threats. OEM manufacturers need to protect themselves from non-authorized
components, discriminate original devices from fake copies, avoid device misuse and
over usage, and make sure customers purchase original equipment.
If we do not take security into account, attackers may try to compromise our devices by:
• Exploiting software bugs
•
Extracting secret device keys
• Inserting counterfeit devices
• Abusing untrusted connections
• Disclosing confidential data, etc
These security threats are significantly serious for IoT systems dealing with real time
processes, even risking safety in case of medical devices, industrial processes, energy
grids or traffic lights automation, among others.
For illustrative purposes, let's assume an OEM which manufactures a certain type
of machinery controlled by a centralized control unit as shown in Figure 1 . As these
machines perform some critical tasks in the manufacturing plant:
• The control unit authenticates the machine that is attempting to connect to it.
•
The machines also authenticate the control unit that will manage it.
Therefore, only authenticated machines and control units will be used in the supply
chain. This mechanism ensures protection against rogue devices that might damage
production, degrading security levels or risking employee safety.
Figure 1. Device-to-device authentication scenario
The exchange of digital certificates is the basis of the authentication process. The two
parties each check that the certificate is valid and was issued by a trusted authority,
known as Certificate Authority. Section 2 describes how certificates are verified using a
certificate chain of trust.
Digital certificates, as public information, are susceptible to be intercepted and be
misused. For this reason, a proof of possession of the certificate private key is an
essential requirement to validate the certificate source. Section 3 describes how to
leverage A5000 to conduct the proof of possession.
The private key must be kept secret and protected. The leakage of any private key
compromises the identity verification and the overall system security. The A5000
provides a trust anchor at the silicon level, providing a tamper-resistant platform capable
of securely storing keys and credentials needed for offline authentication.
AN13500 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2022. All rights reserved.
Application note Rev. 1.0 — 28 March 2022
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