Evidence Locker & Encrypted Document Vaults | Tripart Details

Every piece of evidence behind a milestone is a structured, independently attested object, never a free-text field, never a document sitting on the ledger itself.

Evidence types: an uploaded document, a logged record/event stream, or a self-attested oracle signal, each submitted as its own hash-locked, multi-party-signed contract, distinct from the milestone it supports
Unilateral submission, gated attestation: a party can submit evidence on their own authority; the verifier’s countersignature is what advances it to a status a milestone can actually rely on, the same authorization model that governs fund release, applied to evidence
Documents live in a private, encrypted vault: hardware-key (KMS) encryption at rest, never a shared file store or public bucket, and the ledger stores only a content hash and a storage reference, never the document itself
Access is exclusively through backend-issued, time-limited, presigned links, granted only to parties the ledger already confirms are signatories on that contract
Read-through lazy mirroring: a party’s own copy is cached to their vault on first access, not synchronously replicated everywhere in advance, consistent with each participant’s private, sovereign infrastructure