Day-after-day, private knowledge, resembling location data, pictures, or textual content queries are handed between your machine and distant, cloud-based providers. Your knowledge is encrypted when in transit and at relaxation, however as potential assault vectors develop extra subtle, knowledge should even be protected throughout use by the service, particularly for software program programs that deal with personally identifiable consumer knowledge.

Towards this objective, Google’s Venture Oak is a analysis effort that depends on the confidential computing paradigm to construct an infrastructure for processing delicate consumer knowledge in a safe and privacy-preserving manner: we guarantee knowledge is protected throughout transit, at relaxation, and whereas in use. As an assurance that the consumer knowledge is the truth is protected, we’ve open sourced Venture Oak code, and have launched a clear launch course of to present publicly inspectable proof that the applying was constructed from that supply code. 

This weblog put up introduces Oak’s clear launch course of, which depends on the SLSA framework to generate cryptographic proof of the origin of Oak’s confidential computing stack, and along with Oak’s distant attestation course of, permits customers to cryptographically confirm that their private knowledge was processed by a reliable utility in a safe surroundings. 

Venture Oak lately collaborated with the SLSA group to create a brand new container-based builder that produces Provide-chain Ranges for Software program Artifacts (SLSA) Construct Degree 3 provenance. This new container-based builder generates non-forgeable provenance statements that seize particulars about construct course of data that enable customers to carry out automated, rigorous provenance verification.

With this enhanced provenance generated by the container-based builder, you possibly can reply questions like:

• Was the artifact constructed with a toolchain that I do know and belief?

• Was the artifact constructed with a command that I belief?

• Did the construct command use a device that was affected by a vulnerability?

• How can I recreate the artifact?

Venture Oak is especially excited by answering these questions on each layer of the confidential computing stack. As an illustration, to make certain that a launched binary was constructed utilizing a trusted construct course of (e.g., the construct command didn’t use any probably malicious device), the Oak launch course of compares the construct command towards a set of allow-listed tokens. Equally, we will confirm that the builder was not tampered with. 

Venture Oak develops a safe runtime and a distant attestation protocol—methods to detect potential adversaries on distant servers and to guard workloads whereas they’re working. Now, with the addition of the container-based SLSA builder, we’re in a position to full our clear launch course of to guard towards software program provide chain assaults and supply an automatic course of for verifying the integrity and trustworthiness of a distant server, earlier than sending delicate data to it. 

Particularly, for every launched model of the Oak safe runtime, the Oak staff generates and indicators an endorsement assertion for the binary, utilizing a key accessible solely to the Oak staff. The endorsement assertion can solely be generated if the provenance assertion passes verification checks, guaranteeing {that a} potential malicious attacker can’t forge the assertion.

When the consumer establishes a connection to the server, the consumer should confirm the endorsement assertion and the proof of its inclusion in a transparency log, and verify that the binary identities within the attestation report and the endorsement assertion are the identical. This, along with signature verification for the endorsement assertion, ensures three vital factors of belief for the general course of: that the consumer is interacting with the identical publicly endorsed model of the Oak safe runtime that each one different purchasers work together with; the Oak safe runtime is open supply; and that it has a publicly printed non-forgeable SLSA v1.0 provenance with adherence to SLSA Construct Observe 3. For a extra technical clarification of the method, see Venture Oak’s clear launch course of.

Visualization of an Oak utility, with attestation verification 

We encourage you to take a look at the clear launch undertaking as a use case for SLSA. Please attain out to us by way of our slack channel to discover concepts associated to Oak safe runtimes and distant attestation.

You don’t want to make use of Venture Oak to benefit from the brand new SLSA builder device. In case your undertaking is open supply, strive one of many SLSA builders to generate non-forgeable provenance to your binaries. We encourage you to containerize your construct and take a look at the container-based SLSA 3 builder! Utilizing a container picture to your builds improves the reproducibility of your binaries. We additionally advocate including the directions for constructing your container picture (e.g., a Dockerfile) to your GitHub repository, which improves auditability and transparency of your construct course of, and thus the safety of your software program provide chain.