{
  "schema_version": "1.2.0",
  "rubric_version": "1.1",
  "license": "CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)",
  "record": {
    "id": "K-0014",
    "slug": "network-tap",
    "title": "Network tap",
    "aliases": [
      "TAP",
      "traffic tap"
    ],
    "status": "published",
    "last_reviewed": "2026-09-25",
    "review_interval_days": 90,
    "steward": null,
    "provenance": {
      "drafted_by": "ai",
      "reviewed_by": [
        "codex-review"
      ]
    },
    "risk_flags": [],
    "flags": [],
    "one_liner": "A device that copies the traffic on a network link for inspection without disrupting it; proposed for checking what AI data centres compute.",
    "sources": [
      {
        "source": "S-0031",
        "supports": "definition; passive vs active taps; taps commit to traffic by hashing; front-end links most viable; back-end fabric bandwidth, latency and sampling",
        "locator": "sections on definitions, north-south and east-west links"
      },
      {
        "source": "S-0002",
        "supports": "mutually vetted devices intercept inter-chip data and check against declared uses",
        "locator": "§4.2"
      },
      {
        "source": "S-0018",
        "supports": "fixed-function taps that send hashes of packet groups, not plaintext",
        "locator": "evidence capture"
      }
    ],
    "related": [
      "K-0021",
      "K-0024",
      "K-0019"
    ],
    "type": "concept",
    "url": "https://trustbutveri.fyi/concepts/network-tap/",
    "source_file": "content/concepts/network-tap.md",
    "flags_all": [],
    "body_markdown": "A network tap is a device that copies the traffic on a network link for inspection without disrupting normal operation [[S-0031]].\n\nPassive taps observe without interfering, for example by optically splitting the light in a fibre; active taps interact with the traffic, for instance by re-timing it or modifying headers to reduce covert channels [[S-0031]]. RAND's verification framework includes mutually vetted devices that intercept data exchanged between accelerators and check it for discrepancies with declared uses [[S-0002]]. In proposed designs such as [[M-0013|network taps and certifiers]], taps send out hashes of the traffic as [[K-0024|cryptographic commitments]] instead of plaintext, so that the prover's declarations can later be checked against them [[S-0031]] [[S-0018]]. Cankaya describes taps on the front-end links between a data centre and the outside world as the most viable, because those links carry little bandwidth [[S-0031]]. The back-end fabric between accelerators has far higher [[K-0021|bandwidth]] and strict latency requirements, and may call for random sampling rather than full capture [[S-0031]].",
    "body_text": "A network tap is a device that copies the traffic on a network link for inspection without disrupting normal operation [S-0031]. Passive taps observe without interfering, for example by optically splitting the light in a fibre; active taps interact with the traffic, for instance by re-timing it or modifying headers to reduce covert channels [S-0031]. RAND's verification framework includes mutually vetted devices that intercept data exchanged between accelerators and check it for discrepancies with declared uses [S-0002]. In proposed designs such as network taps and certifiers, taps send out hashes of the traffic as cryptographic commitments instead of plaintext, so that the prover's declarations can later be checked against them [S-0031] [S-0018]. Cankaya describes taps on the front-end links between a data centre and the outside world as the most viable, because those links carry little bandwidth [S-0031]. The back-end fabric between accelerators has far higher bandwidth and strict latency requirements, and may call for random sampling rather than full capture [S-0031].",
    "referenced_by": [
      {
        "id": "M-0013",
        "title": "Network taps and certifiers",
        "url": "https://trustbutveri.fyi/mechanisms/network-taps-and-certifiers/"
      },
      {
        "id": "M-0003",
        "title": "Whole-workload recomputation (reproducible packets)",
        "url": "https://trustbutveri.fyi/mechanisms/reproducible-computation-packets/"
      },
      {
        "id": "M-0001",
        "title": "Sampled inference recomputation",
        "url": "https://trustbutveri.fyi/mechanisms/sampled-inference-recomputation/"
      },
      {
        "id": "M-0022",
        "title": "Side-channel suppression for isolated facilities",
        "url": "https://trustbutveri.fyi/mechanisms/side-channel-suppression/"
      },
      {
        "id": "M-0005",
        "title": "Zero-knowledge proofs of training constraints",
        "url": "https://trustbutveri.fyi/mechanisms/zk-proofs-of-training-constraints/"
      },
      {
        "id": "I-0011",
        "title": "AI 2040 inference-only verification stack",
        "url": "https://trustbutveri.fyi/implementations/ai-2040-inference-only-verification-plan/"
      },
      {
        "id": "I-0012",
        "title": "Low-trust AI compute verification system overview",
        "url": "https://trustbutveri.fyi/implementations/low-trust-compute-verification-system-overview/"
      },
      {
        "id": "I-0008",
        "title": "SASH confidential network logger",
        "url": "https://trustbutveri.fyi/implementations/sash-confidential-network-logger/"
      },
      {
        "id": "C-0008",
        "title": "Communication between compute groups is bounded",
        "url": "https://trustbutveri.fyi/claims/bandwidth-is-bounded/"
      },
      {
        "id": "C-0004",
        "title": "This compute runs inference, not training",
        "url": "https://trustbutveri.fyi/claims/inference-not-training/"
      },
      {
        "id": "C-0009",
        "title": "Model weights have not left the facility",
        "url": "https://trustbutveri.fyi/claims/weights-have-not-left/"
      },
      {
        "id": "K-0017",
        "title": "Compartmentalization",
        "url": "https://trustbutveri.fyi/concepts/compartmentalization/"
      },
      {
        "id": "K-0024",
        "title": "Cryptographic commitment",
        "url": "https://trustbutveri.fyi/concepts/cryptographic-commitment/"
      },
      {
        "id": "K-0021",
        "title": "Interconnect bandwidth",
        "url": "https://trustbutveri.fyi/concepts/interconnect-bandwidth/"
      },
      {
        "id": "K-0022",
        "title": "Weight exfiltration",
        "url": "https://trustbutveri.fyi/concepts/weight-exfiltration/"
      }
    ]
  }
}