Legal Evidence Packs and Litigation Hold Rooms

Immutable contract versioning on the Arweave blockchain. Every amendment creates a new transaction linked to its predecessor - forming a cryptographically verifiable modification chain that spans decades.

Audit trails no one can alter.

Legal data infrastructure is fundamentally fragile.

Key challenges

Contract tampering is an active threat

Legal contracts stored in mutable file systems - SharePoint, Google Drive, email - can be modified after signing. Without a cryptographic record, proving what a document said at a specific point in time is extraordinarily difficult.

Manual audit logs are unreliable

Traditional audit logs stored in a database controlled by one party carry no evidentiary weight - a privileged database administrator can ALTER, DELETE, or fabricate log entries without detection.

Regulatory retention requirements are strict

Financial services, healthcare, and government contracts often require document retention for 7, 10, or more years. Maintaining compliant archives with access controls is operationally expensive.

How Evercore satisfies regulators.

Solution

Encrypted at rest

Legal documents are encrypted with AES-256-GCM before upload. Only parties with API access can decrypt - the permaweb stores opaque ciphertext.

Semantic version chain

Each amendment creates a new Arweave TX with a Parent-TX tag. The linked list is reconstructable from any version in the chain.

Blockchain-timestamped

Arweave block heights serve as immutable timestamps. The exact Arweave block at time of upload is permanently recorded on-chain.

Scoped read access for auditors

Issue a bearer token with versions:read scope to external auditors. They can traverse the version chain without write access.

Evidence-grade infrastructure, not another shared drive.

Treat each contract version as a transaction: ordered by consensus, linked by hash pointers, and independently verifiable by opposing counsel or a court-appointed expert.

• Tamper-evident chain: Parent-TX tags link each version to the prior transaction; omitting or reordering versions shows up as a broken chain when you walk the history.
• Global time oracle: Block timestamps are agreed by the network, not your IT admin. Useful for statute-of-limitations arguments and proving signing order.
• Ciphertext privilege: Encrypt before upload so Evercore and gateways never hold usable documents - narrow what third parties could theoretically produce under subpoena.
• Public verifiability: Anyone with the TX ID can confirm the bytes on-chain match your disclosed hash - no proprietary viewer required.

Is a timestamped Arweave transaction legally admissible?

Arweave transactions include a block timestamp verified by network consensus. While admissibility varies by jurisdiction, cryptographic proof of existence at a given time is increasingly recognized in e-discovery and contract disputes. Consult legal counsel for your specific jurisdiction.

Can opposing counsel subpoena Evercore for document contents?

Evercore never stores encryption keys or plaintext. We cannot produce document contents under subpoena - only the encrypted bytes that exist on-chain. Key custodianship remains entirely with your team.

How do I prove document integrity in court?

Provide the TX ID and the Arweave block hash to verify the transaction. The SHA-256 hash of the ciphertext is embedded in the Arweave transaction and verifiable by any third party without Evercore involvement.