[dane-pgp]

Ultimately the system will need to support signatures which represent not just "I made this" but "I reviewed this", and people will need to set policies for whose reviews they trust, and how many reviews they require for each component.

If reviewers can build up a reputation anonymously, that will make it harder to find the human who needs to be crowbarred, but I'm not sure how you prove you are a good reviewer in a way which isn't gameable.

Alternatively, the reviewers could be well known teams in multiple jurisdictions, such that an attacker would need to buy multiple crowbars and multiple plane tickets.

[BenTheElder]

Those are interesting points / possible approaches, however is there any indication that this particular project enables any of that?

This seems focused on signing binaries / build artifacts.

IMHO it seems like if you have the threat model of "crowbared maintainer forced to insert backdoor" you probably don't trust sources let alone binaries and need to vet your dependency sources and then compile your own binaries from them.

Many open source dependencies will not have a jurisdictionally diverse review team, or any review team at all (single maintainer).

[dane-pgp]

With reproducible builds, the difference between signing a binary and signing the source code from which it is built should be meaningless.

I agree that the threat model should include the threat of untrustworthy source code, because we want the countermeasures to work equally well against backdoors, "bugdoors", and genuine bugs.

[BenTheElder]

Good points.

I suspect for a lot of projects reproducible builds are themselves a bit of a hurdle and not being verified in the rarer case that they already exist, but the point of reproducible + signed builds as indirect source-signing stands.

[the_duke]

The reviewing aspect sounds a lot like cargo-crev. [1]

[1] https://github.com/crev-dev/cargo-crev