Apple Intelligence is capable of processing tasks locally on Apple devices whenever possible. However, some more complex tasks require additional processing power and access to larger-scale platform models. To enable Apple devices to access this additional AI processing power in the cloud, Apple developed Private Cloud Compute (PCC). The Cupertino company claims that PCC provides privacy and security protections to support the compute-intensive requirements of Apple Intelligence by extending its on-device security model to the cloud.
To validate the security of PCC, Apple initially allowed a group of security and privacy researchers to thoroughly test and verify the system. This was accomplished by sharing the PCC Virtual Research Environment (VRE) with third-party reviewers and the aforementioned group of researchers. Apple is now making these resources publicly available so that security and privacy researchers around the world can conduct their own independent verification processes.
Apple has also publicly released the source code for key components of PCC, including:
- The CloudAttestation project is responsible for building and validating PCC node attestations.
- The Thimble project includes a privatecloudcomputed daemon that runs on the user's device and uses CloudAttestation to enforce verifiable transparency.
- The splunkloggingd daemon filters logs that may be emitted from a PCC node to protect against accidental data disclosure.
- The srd_tools project contains the VRE tools and can be used to understand how the VRE allows running PCC code.

In addition, Apple also announced that its Security Bounty program now includes the PCC category. Apple's willingness to pay for PCC vulnerabilities demonstrates the company's commitment to PCC security claims. For cases of arbitrary code execution vulnerabilities in PCC, Apple is willing to pay up to $1 million. If an issue is found that provides access to user request data or sensitive information, Apple will pay $250,000.
With these moves, Apple is really looking to build trust and transparency around PCC, as well as reinforce its commitment to protecting user privacy and security in the cloud.