Three Architectural Principles

Three properties that determine whether an information system survives triggering events over long time horizons. Together they constitute the analytical vocabulary against which the four-tier taxonomy (M-0001) is constructed.

Distribution across independent failure domains. A failure domain is the scope within which a single event can cause total loss. Servers, organizations, funding sources, and jurisdictions are each failure domains. For a dataset to survive a triggering event, independent copies must exist in failure domains that the event does not reach. Concentration of copies inside a single failure domain — however reliable that domain appears — produces single-event loss.

Verifiable integrity. When data integrity depends on the assertion of the holder, verification is procedural and depends on the holder's continued cooperation. When data is identified by a cryptographic hash of its contents, verification is mathematical: any recipient can independently confirm that the bytes received are identical to the bytes originally published, without trusting any intermediate party. RFC 6920 (S-0010) formalizes the approach; Git, IPFS, and Software Heritage implement it.

Organizational independence. Any preservation system requiring an organization's continued commitment inherits that organization's failure modes — governance change, budget cut, acquisition, operational collapse, strategic reprioritization, jurisdictional action. Protocols that produce additional copies as a byproduct of use — Git's clone, BitTorrent's seeding, DNS caching — deliver resilience that does not depend on any single organization continuing to maintain it. The act of use is the act of contributing to redundancy.

These three principles are independent properties. A system can satisfy one without satisfying the others; only their joint presence produces Tier 3 resilience. The four-tier taxonomy (M-0001) classifies architectures by how many of the three principles they embody.