What this page covers
Custodea-like platforms provide storage and data lake infrastructure. Attesto adds the evidence layer that proves what happened to data, when, under which policy and without exposing raw records.
Evidence question
How Custodea can prove EU data residency with Attesto answers a concrete audit question: what must be retained so a third party can verify the relevant event chain later?
- Which event happened and which system produced it.
- Which policy, model, supplier or human approval was active.
- Which hash, signature, Merkle root and verifier receipt prove integrity.
Attesto proof layer
Attesto complements GRC, SIEM, storage and workflow systems by sealing selected evidence records instead of replacing the operating system.
- Raw data can remain encrypted or customer-controlled.
- Proof material can be shared with auditors or customers.
- A verifier can test whether a record still matches the anchored root.
Legal timing
NIS2 was due for national transposition by 17 October 2024. National implementation differs by Member State, but incident and control evidence should be retained before an authority or customer asks for it.
This page is implementation guidance for evidence planning, not legal advice.
Evidence Attesto AI can preserve
API event
access event
supplier attestation
Merkle inclusion proof
auditor verification receipt
Example evidence records
Example proof receipt
Example Attesto receipt
event_type
CUSTODEA_DATA_RESIDENCY
timestamp
2026-06-04T10:21:00Z
leaf_hash
sha256:8f41...b19e
merkle_root
sha256:52ac...91d4
anchor_reference
attesto:anchor:2026-06-04:eu-001
verification_status
valid demo receipt, raw data not exposed
Where Attesto fits
The case is framed as an evidence model, not a fake customer claim. It shows what Attesto can add when a provider wants verifiable customer-facing proof.
FAQ
How is this different from a normal log?
A normal log asks an auditor to trust the system that produced it. Attesto records hashes, signatures, Merkle proofs and verifier receipts so selected evidence can be checked independently.
Does Attesto need to expose raw sensitive data?
No. Raw records can remain encrypted or customer-controlled while proof material is shared for verification.
Where does How Custodea can prove EU data residency with Attesto fit in the compliance stack?
The case is framed as an evidence model, not a fake customer claim. It shows what Attesto can add when a provider wants verifiable customer-facing proof.