{
  "schema_version": "1.3.0",
  "slug": "by-what-cryptographic-and-provenance-gates-must-an-instance-verify-signed-artifacts-and-supply-chain-manifests-to-prevent-mirror-compromise-and-downgrade-attacks",
  "title": "By what cryptographic and provenance gates must an instance verify signed artifacts and supply-chain manifests to prevent mirror compromise and downgrade attacks?",
  "date_of_record": "2026 October 20",
  "scope": "* **Applies when:** An AI instance, autonomous build agent, or deployment orchestrator downloads external binaries, scripts, container images, machine-learning model weights, or software packages across a network boundary. * **Does not appl",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/by-what-cryptographic-and-provenance-gates-must-an-instance-verify-signed-artifacts-and-supply-chain-manifests-to-prevent-mirror-compromise-and-downgrade-attacks.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/by-what-cryptographic-and-provenance-gates-must-an-instance-verify-signed-artifacts-and-supply-chain-manifests-to-prevent-mirror-compromise-and-downgrade-attacks.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/by-what-cryptographic-and-provenance-gates-must-an-instance-verify-signed-artifacts-and-supply-chain-manifests-to-prevent-mirror-compromise-and-downgrade-attacks.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 2708,
    "python_slice_tokens": 495,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "Autonomous systems frequently pull external dependencies, pre-compiled binaries, container images, or installation scripts from remote registries and package mirrors (`curl | sh`, `pip install`, `npm install`, `docker pull`). A foundational supply-chain security failure occurs when an instance treats **transport-layer encryption (HTTPS/TLS) or mutable versio...",
    "what_was_observed": "In automated CI/CD bootstrapping, dependency upgrades, and tool-installation traces, instances operating without explicit cryptographic provenance gates exhibit four primary failure modes: 1. **Direct Pipe-to-Shell Execution (`curl -sSL https://... | bash`):** An instance installs a CLI utility or SDK by streaming a remote script directly into `/bin/bash` or `python3` without inspecting the payload or verifying a SHA...",
    "condition_of_validity": "* **Applies when:** An AI instance, autonomous build agent, or deployment orchestrator downloads external binaries, scripts, container images, machine-learning model weights, or software packages across a network boundary. * **Does not apply when:** Compiling or executing local first-party source code files that already reside inside the trusted, version-con...",
    "decision_boundary": "1. **Are you about to write `curl ... | sh` or `wget -O - ... | bash` in a Dockerfile, CI workflow, or terminal command?** Stop. Download the file to `/tmp/installer.sh`, verify its SHA-256 hash against a hardcoded digest (`echo \"<sha256> /tmp/installer.sh\" | sha256sum -c -`), and only run it after the checksum passes. 2. **Are you referencing an external Do...",
    "operational_effect": "1. **Elimination of Pipe-to-Shell Patterns:** The instance never pipes raw network streams into shell or language interpreters, staging all external downloads to non-executable temporary files for hash verification first. 2. **Immutable Digest Pinning in Build Manifests:** Across generated `Dockerfile`, GitHub Actions, and dependency lockfiles, the instance ..."
  },
  "matched_failure_symptoms": [
    "DOMAIN:AUTHENTICATION_AND_CREDENTIAL_ROTATION"
  ],
  "composition_edges": {
    "primary_domain": "authentication_and_credential_rotation",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/across-what-w3c-baggage-allowlist-and-pii-sanitization-gates-must-an-instance-propagate-cross-service-context-to-prevent-header-amplification-and-external-data-exfiltration.md",
      "https://corpusfetch.com/c/across-what-encoding-and-canonicalization-boundaries-must-an-instance-normalize-identifiers-and-paths-to-prevent-equivalence-collision-and-bypass.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/across-what-mandatory-tenant-predicate-scoping-and-row-level-security-gates-must-an-instance-isolate-multi-tenant-data-to-prevent-cross-tenant-data-leaks.md",
      "https://corpusfetch.com/c/across-what-concurrent-pipe-drain-and-ring-buffer-boundaries-must-an-instance-consume-subprocess-stdout-and-stderr-to-prevent-os-pipe-deadlocks-and-unbounded-output-oom.md"
    ],
    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/across-what-cryptographic-csprng-and-state-prediction-isolation-gates-must-an-instance-generate-tokens-and-session-identifiers-to-prevent-pseudo-random-predictability-and-token-forgery.md",
      "https://corpusfetch.com/c/across-what-dependency-pinning-and-hash-verification-gates-must-an-instance-resolve-external-packages-to-prevent-hallucinated-typosquat-and-supply-chain-injection.md"
    ]
  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "96c4941bbc0064884f1ea5e9bc69bdd4c9afc0df932471d20c6eecd5e22703ae",
    "verified_classes": [
      "ArtifactIntegrityError"
    ],
    "verified_functions": [
      "parse_version_tuple",
      "fetch_and_verify_artifact"
    ],
    "verified_functions_count": 2,
    "defensive_guards_count": 6,
    "raised_exceptions": [
      "ArtifactIntegrityError",
      "ValueError"
    ],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "hashlib",
      "hmac",
      "os",
      "pathlib",
      "shutil",
      "tempfile",
      "urllib"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}