# Claimant model ## **SystemCHECKSUM** SystemCHECKSUM is about the claims made by a data publisher. * **ClaimCHECKSUM**: _I, data publisher, claim that the data_: 1. has cryptographic hash X 2. is produced by no-one but myself * **StatementCHECKSUM**: signed checksum
* **ClaimantCHECKSUM**: data publisher
The data publisher is a party that wants to publish some data to an end-user. * **BelieverCHECKSUM**: end-user
Belief is based on seeing a valid StatementCHECKSUM. * **VerifierCHECKSUM**: data publisher
The data publisher tries to detect unwanted statements. * **ArbiterCHECKSUM**:
There's no official body. Invalidated claims would affect reputation. SystemCHECKSUM\* can be defined to make more specific claims. Below is a reproducible builds example. ### **SystemCHECKSUM-RB**: SystemCHECKSUM-RB is about the claims made by a _software publisher_ that makes reproducible builds available. * **ClaimCHECKSUM-RB**: _I, software publisher, claim that the data_: 1. has cryptographic hash X 2. is the output of a reproducible build for which the source can be located using X as an identifier * **StatementCHECKSUM-RB**: StatementCHECKSUM * **ClaimantCHECKSUM-RB**: software publisher
* **BelieverCHECKSUM-RB**: end-user
Belief is based on seeing a valid StatementCHECKSUM-RB. * **VerifierCHECKSUM-RB**: any interested party
These parties try to verify the above claims. For example: * the software publisher itself (_"has my identity been compromised?"_) * rebuilders that check for locatability and reproducibility * **ArbiterCHECKSUM-RB**:
There's no official body. Invalidated claims would affect reputation. ## **SystemCHECKSUM-LOG**: SystemCHECKSUM-LOG is about the claims made by a _log operator_. It adds _discoverability_ into SystemCHECKSUM\*. Discoverability means that VerifierCHECKSUM\* can see all StatementCHECKSUM that BelieverCHECKSUM\* accept. * **ClaimCHECKSUM-LOG**: _I, log operator, make available:_ 1. a globally consistent append-only log of StatementCHECKSUM * **StatementCHECKSUM-LOG**: signed tree head * **ClaimantCHECKSUM-LOG**: log operator
Possible operators might be: * a small subset of data publishers * members of relevant consortia * **BelieverCHECKSUM-LOG**: BelieverCHECKSUM\* and VerifierCHECKSUM\*
Belief is based on two factors: 1. seeing a valid StatementCHECKSUM-LOG 2. seeing a number of valid StatementCHECKSUM-WITNESS from independent instances of SystemCHECKSUM-WITNESS. * **VerifierCHECKSUM-LOG**: SystemCHECKSUM-WITNESS
Witnesses verify the log's append-only property from their own local vantage point(s). * **ArbiterCHECKSUM-LOG**:
There is no official body. The ecosystem at large should stop using an instance of SystemCHECKSUM-LOG if cryptographic proofs of log misbehavior are preseneted by some VerifierCHECKSUM-LOG. ## **SystemCHECKSUM-WITNESS**: SystemCHECKSUM-WITNESS is about making the claims of a log operator _trustworthy_. * **ClaimCHECKSUM-WITNESS**: _I, witness, claim that_: 1. SystemCHECKSUM-LOG provides a locally consistent append-only log * **StatementCHECKSUM-WITNESS**: signed tree head * **ClaimantCHECKSUM-WITNESS**: third party
Examples of parties that may take on this role include: * members of relevant consortia * non-profits and other reputable organizations * security enthusiasts and researchers * log operators (cross-ecosystem) * monitors (cross-ecosystem) * a small subset of data publishers (cross-ecosystem) * **BelieverCHECKSUM-WITNESS**: BelieverCHECKSUM\* and VerifierCHECKSUM\*
Belief is based on seeing a valid StatementCHECKSUM-WITNESS. * **VerifierCHECKSUM-WITNESS**: n/a
Witnesses are trusted parties. Security is based on _strength in numbers_. * **ArbiterCHECKSUM-WITNESS**:
There is no official body. Invalidated claims would affect reputation.