Hardware switches that follow TPM policy, not software.
Every discrete TPM 2.0 can drive general-purpose I/O pins directly. With Secure GPIO, sensitive functions stay physically disabled by default and are enabled only when the TPM's security conditions are met.
A GPIO that software can't simply flip
An ordinary GPIO
- Any software that reaches the pin can switch it
- A compromised OS, malicious application or remote attacker inherits that control
- Enforcing rules needs a separate secure microcontroller
Secure GPIO
- The pin follows the TPM's security policy
- It changes state only when the TPM's conditions are met
- No separate secure microcontroller - the TPM 2.0 is already on the board
Hardware decisions under TPM control
Tamper and lid-open detection
A TPM GPIO pin senses a chassis-intrusion switch, a lid-open contact or a tamper mesh, so tampering is seen by the TPM itself, not reported by software that may be compromised.
Authorized actuator power
Motor and actuator power is switched on only when the TPM's policy conditions are met - for example a known boot state, or a request backed by the right credential.
Radio and modem gating
The radio or cellular modem stays off until the TPM's conditions are met, so a compromised system can't simply switch on a link to call home or be reached remotely.
Where it usually gets hard
Configuring the TPM's GPIO pins and writing the authorization policies that decide when a pin may change state means working directly with the TPM and its specification. EnactTrust handles this, so your team decides which signals to protect, not how.
What to know
Outputs and inputs
As an output, a pin switches hardware on and off. As an input, it lets the TPM sense a chassis-intrusion switch, a tamper mesh or a service jumper.
Policy-controlled
A pin can change state only in a known boot state, only when someone with a specific credential or signed approval asks, or only once per boot before it locks.
Any discrete TPM 2.0
Works with every discrete TPM 2.0 - Infineon, Nuvoton, STMicroelectronics and others - and the signals behave the same way on SPI and I²C platforms.
Board traces still matter
The pin's electrical signal leaves the chip, so physical protection of the board traces still matters. Pair it with tamper detection.
Start with a conversation
Secure GPIO is available on request. Tell us which signals on your platform belong under TPM control.
Book a discovery call