The Evidence
Vault.
Moving from standard spreadsheets to a tamper-proof "Evidence Vault." Every row is digitally sealed with SHA-256 hashing to ensure absolute data integrity.
Spreadsheets are
Mutable.
A standard Google Sheet is a living document. This is great for collaboration, but dangerous for evidence. If a row is changed, deleted, or manipulated, there is often no permanent record of the *original* state.
The Evidence Vault treats every entry as a "Record of Fact," sealing it the moment it is written.
Digital Signature
We hash the entire row data into a unique string. If a single character changes, the hash breaks.
Non-Repudiation
Provides mathematical proof of exactly what was submitted and when, making it ready for legal or audit review.
How it
Seals.
Data Ingestion
Receives high-integrity data from the Forensic Shield and normalises the payload.
SHA-256 Hashing
Generates a unique cryptographic fingerprint for the entire row of data.
Digital Sealing
Appends the hash to the row, creating an immutable link to the original state.
Chain of Custody
Logs the exact timestamp and administrative context of the digital seal.
Audit Ready
Provides a tamper-proof dashboard for legal or professional verification.
The "Seal"
Architecture.
Using Google Apps Script's native `Utilities.computeDigest` method, we create a SHA-256 hash of every incoming row.
Data Normalisation
We flatten the row into a deterministic string (joining all fields with pipe delimiters).
Cryptographic Hashing
The string is passed through the SHA-256 algorithm to generate a unique 64-character signature.
Immutable Append
The seal is written to a hidden, protected column that cannot be edited by standard users.
Need Unbreakable
Integrity?
Don't leave your data to chance. Let's build an Evidence Vault that turns your spreadsheets into a mathematically proven source of truth.
Deploy an Evidence Vault