The piece that might be of interest to you is the interaction between content-addressed and input-addressed content in light of build systems+software+compilers that are not bit-reproducible. There is also the bookkeeping to ensure auditability by third-parties; anyone else can run the same builds and expect the same outcome, or close enough that the differences become easy to find and report upstream (https://r13y.com/), but the system doesn't require bit-reproducibility from day1 because that would be impractical. Of course substituting from a cache is exact, made possible by the signatures.
Remote builds: https://nixos.org/manual/nix/stable/advanced-topics/distribu...
Signing (i'll amend my claim above to be only 1 decade). These are either signatures of a CA path, or for input-addressed things it can be seen as a claim by the signer that the producing build recipe (we call it "derivation") has this particular binary output.
- https://nixos.org/manual/nix/stable/command-ref/nix-store/ge...
- https://nixos.org/manual/nix/stable/advanced-topics/post-bui...
- https://nixos.org/manual/nix/stable/command-ref/conf-file.ht...
- https://nixos.org/manual/nix/stable/command-ref/conf-file.ht...
- example: see the Signatures line for an example that this this specific provenance produced this specific binary output: https://trusted-friendly-sesame.glitch.me/view.html?cache_ba... or https://cache.nixos.org/7ghhnlwla2mddkg7hgqa5v0sr8g5hga8.nar...