{
  "handle": "FullCryptographicChange",
  "gloss": "A parasitic function that rides on a host process, occupying the same states without needing any prediction, and paying only in delay",
  "mechanism": "The most complete form of {{cryptographic_change}}. A second function is carried out entirely within a host process's existing activity: no input is skipped and nothing is removed, so the host's specification, cost and output are unchanged. The parasitic function needs two things: to find the resources it requires as a subset of what the host already processes, and to tolerate delay, since it only advances when the host happens to carry it. It is powered by the host's budget and costs only the opportunity of faster delivery. Examples: a message encoded as positions of words in a book someone appears simply to be reading; waiting for an errand that passes the shop where the person you want to meet works; recycling dropped off on a trip already passing the depot; SETI searching data from telescope time funded for other research. Defining a function as time-insensitive lets it be carried this way at almost no cost, which suits low-carbon logistics.",
  "invariants": [
    "The host process's inputs, outputs and cost are unchanged",
    "The parasitic function occupies the same states as the host, not freed room",
    "Its cost is delay, not processing"
  ],
  "preconditions": [
    "The host process has enough variety and runs long enough to carry the parasitic function",
    "The parasitic function tolerates delay"
  ],
  "failure_modes": [
    "Expecting time-sensitive functions to be carried this way",
    "Hosts too monotonous or too short to carry the function",
    "Treating any activity that piggybacks on another as costless, ignoring the delay"
  ],
  "_meta": {
    "path": [
      "Infrastructure",
      "Primitives"
    ],
    "ring": 2,
    "tier": 2,
    "caution": "A function hidden inside a host process runs outside the view of whoever is accountable for that process.",
    "source": "Adam Timlett, On the Origin of Risk (2025), Technical Appendix III p.165-168"
  },
  "sema_id": "sema:FullCryptographicChange#mh:SHA-256:8ded38dc1ec73912225e20273a75efd77caf73d44a6c4116da9678e2f8990532",
  "sema_ref": "FullCryptographicChange#8ded",
  "sema_stub": "8ded",
  "dependencies": {
    "references": {
      "cryptographic_change": "sema:CryptographicChange#mh:SHA-256:b5bca2d05d1d78791bc7caa60a3653f88e54d8cf94dae9e809a33345be9d28ea"
    }
  },
  "sema_layer": "Infrastructure",
  "sema_category": "Primitives",
  "used_by": {}
}