Security issues in Protected PCIe mode

Accelerated Computing Confidential Computing
1

According to https://docs.nvidia.com/570TRD1-trusted-computing-solutions-release-notes.pdf, in Protected PCIe (PPCIe) mode,

In this mode, GPU-GPU communications over the NVLink/NVSwitch are not encrypted.

Could data transmitted over NVLink/NVSwitch be compromised in the case of physical attack?

2

Could data transmitted over NVLink/NVSwitch be compromised in the case of physical attack?

That is correct. That said, there are a couple of general and practical considerations to take into account.

  1. Since NVLink is a proprietary technology then it may be difficult for an attacker to obtain a protocol analyzer that can monitor and decode data on the wire. I assume they’re not as freely available as their PCIe counterparts.
  2. Assuming an attacker has access to such an analyzer, the PCB and its traces will (probably) need modification to insert the monitor.
  3. Assuming an attacker has successfully completed 1 and 2, the wire may be perturbed such that it results in performance degradation and/or data corruption, such that the end user may detect this condition.

To meet customer demand, PPCIe was designed with an explicit tradeoff between performance and security.

4

Thank you! By the way, has Nvidia released the deployment guide of pPCIe mode?