entanglement-proof

What is entanglement-proof and what is it for?

entanglement-proof is software that records the links between the different cryptographic keys a person or device uses, so that keys belonging to the same identity can be recognised as connected. It was written as a Language — a plug-in module — for AD4M, the framework its repository sits under, and it stores those key links as signed data that other AD4M instances can read and check.

entanglement-proof is a small, single-purpose component published under the coasys GitHub organisation. Its README describes it in one line: a language for storing AD4M entanglement proofs, that is, the proof that associated different cryptographic keys to each other. In AD4M's terms it is a Language: a plug-in module that takes signed data, stores it and hands back an address, loaded by an AD4M instance rather than launched on its own.

The problem it addresses is key sprawl. One person may hold a long-term identity key plus a separate key for each device they use, and other people need a way to confirm that those keys speak for the same person. An entanglement proof is that confirmation in data form: an identity key and a device key sign for one another, and the proof is stored so it can be looked up later. Because it is signed in both directions, the association can be checked from either side.

One concrete case is adding a second device: the new device key and the existing identity key can be linked so other participants can treat the new key as belonging to the same person. AD4M's own reference describes an EntanglementProof as carrying the identity, the signing key identifier, the device key and its type, and both cross-signatures. The repository README and AD4M's documentation at docs.ad4m.dev are the available sources. hAppRadar's census records this repository as stalled, with no published release and its last recorded push in August 2021, and no installation or run instructions are published; it is a historical record of an early AD4M component rather than software with a documented way to run it.

From 4 public sources, checked 23 September 2026.