# Why this approach is safe

By Josef Long. Published October 17, 2026.

The clearest way to explain how VaultScribe protects client data is to follow one client call from the moment it starts until the day its key is destroyed. Then the threats, the encryption, and who holds the keys.

## The short version

Client data stays on the firm's own machines, so there is no vendor copy to breach. Everything stored is encrypted with 256-bit keys, with a separate key for each matter, recording and voiceprint, and the firm holds the keys. Anything that leaves goes through one door and is logged. Deleting a record means destroying its key, and the proof is a signed certificate.

## One client call, start to finish

1. 10:00, the call starts. VaultScribe asks on your computer whether to transcribe. No bot joins, and no third party is in the room.
2. 10:00, the recording is encrypted as it is written. The matter's key protects it from the first second. The capture process is designed not to write a plaintext file.
3. 10:42, notes and a deadline are drafted. The speech and AI models run on your computer, in a sandbox with no network access. They produce a summary, next steps and a proposed deadline.
4. 10:50, a lawyer reviews. The notes stay marked as AI-generated until a lawyer signs off. The deadline stays a proposal until it is confirmed.
5. 10:58, you click Send. The follow-up email goes out through your own account. One line is added to the log: when, where and why, never what was sent.
6. Two years later, the retention period ends. The matter's key is destroyed. The data becomes unreadable wherever a copy might sit, including backups.
7. Same day, a certificate is issued. It records what was destroyed, why, and that no legal hold covered it. It is signed, so anyone can verify it.

## The boundary around your data

Everything in that story happens inside one boundary. The firm's computers, and optionally a firm server, hold the data and the keys. One door leads out, and every request through it is logged. Outside the boundary are connectors the firm opts into and cloud AI that is off by default. VaultScribe, the company, holds no client data.

## What happens if something goes wrong

In a typical cloud service, many firms' recordings sit in one place, so one breach reaches all of them. With VaultScribe there is no vendor-run central store to breach, and each firm's files are encrypted under that firm's own keys, on the firm's own machines or its own server.

## The threats, one by one

| Threat | Cloud AI service, often | VaultScribe |
|---|---|---|
| A breach of the vendor's servers | Many customers' recordings and transcripts sit in one place to steal. | The vendor holds no client data, so there is nothing at the vendor to steal. |
| A lost or stolen laptop | Depends on the disk and the user's settings. | Content is encrypted at the application level whether or not the disk is. The top key sits in the security chip, and an idle lock wipes keys from memory. |
| A curious person inside the firm, or an administrator | Often able to read everything the tool holds. | Matter walls are enforced by keys and policy. Administrator roles do not include matter content. |
| A document or email that tries to instruct the AI | The text may be followed as if it were an instruction. | Outside text is read in a quarantined step that cannot write or send. Anything that sends data out waits for a click. |
| A tampered update or a swapped AI model | The customer trusts the vendor's delivery. | Releases, updates and models are signed and verified before they run. |
| Someone editing the logs afterward | Logs can often be changed by an administrator. | The audit log is chained and signed, so an edit or deletion shows. |

## The encryption, method by method

Stored content, including audio, video, transcripts, notes, the search index, caches and temporary files, is encrypted at the application level, whether or not the disk is also encrypted.

| What it protects | Method | Why this one |
|---|---|---|
| Notes, transcripts, search index | AES-256 | The standard for strong symmetric encryption, with a separate key for each matter. |
| Recordings and files | ChaCha20-Poly1305 | Authenticated encryption: hides the content and detects any change to it. |
| Passwords and recovery codes | Argon2id | Deliberately slow and memory-hungry, which makes guessing expensive. |
| Recovery keys | HPKE | Wraps recovery keys to the firm's own escrow key, which can be split among several people. |
| Releases, updates, models, audit checkpoints | Ed25519 | Proves each item came from who it claims and has not changed. |
| Fingerprints of files and log entries | SHA-256, BLAKE3 | Any change to a file or a log entry changes its fingerprint. |
| The top key | TPM 2.0, Secure Enclave | Where the computer has a security chip, the key lives in it and cannot be copied off. |
| Anything permitted to leave | TLS | Whatever the firm allows out is encrypted in transit. |

## Who holds the keys

The firm does. A separate key protects each matter, each recording, and each person's voiceprint, which is kept in its own registry. Matter keys are released only by a policy decision for a stated purpose and a limited time. The top key sits in the computer's security chip where there is one. Recovery belongs to the firm, and VaultScribe does not hold it.

## One door out, and proof you can check

Every outside connection needs a configured integration and an allowed host. Each request is written to an append-only log the user can read, and the log can be exported as a CSV or a signed copy. A verification kit lists the hosts an installation may contact, runs a firewall test, and includes a software bill of materials, so the claim can be checked with your own firewall.

## Deleting, and proving it

When a record reaches the end of its retention period, or a client asks for deletion, its key is destroyed and the data becomes unreadable. A legal hold stops that for the matters it covers. The audit log is chained entry to entry, with signed checkpoints, so a firm can prove what happened without keeping the content.

## Software and AI you can trust

- Every release, update and AI model is signed and verified before it runs, and models are verified offline.
- A software bill of materials ships with each release.
- Text inside a document or email is read in a quarantined step that can read but not write or send, and anything that would send data out waits for a person. See https://vaultscribe.app/legal-ai-agent.md.

## What about quantum computers?

1. Stored data uses 256-bit symmetric encryption. Quantum computers are widely expected to weaken this far less than they break today's public-key methods, and 256-bit keys are generally regarded as keeping a wide margin.
2. The public-key parts, used for wrapping recovery keys and for signing, are the ones to watch. They are the part quantum computers could eventually break.
3. The practical risk is "harvest now, decrypt later". Keeping client data on the firm's own machines, with no vendor copy and no routine uploads, leaves far less to harvest.

## Questions

**What encryption does VaultScribe use?** AES-256 and ChaCha20-Poly1305 for stored content, Argon2id for passwords and recovery codes, HPKE for recovery keys, Ed25519 signatures, and TLS for anything permitted to leave.

**Who holds the encryption keys?** The firm. The top key is held by the security chip where one exists. VaultScribe does not hold the firm's recovery keys.

**Is VaultScribe safe against quantum computers?** Stored data uses 256-bit symmetric encryption. The public-key parts, used for key recovery and signing, are the ones quantum computers could eventually break.

**Can I check these claims myself?** Yes. Every outside request is written to a log you can read, and a verification kit lists the hosts an installation may contact, runs a firewall test, and includes a software bill of materials.

**What happens if a document tries to instruct the AI?** It is read in a quarantined step that cannot write or send, and any action that would send data out waits for a person.

**Where is client data stored?** On the firm's own machines and, optionally, a firm server. VaultScribe, the company, holds no client data.

Questions about security? hello@vaultscribe.app. Founding design partners sign a non-binding letter of intent, with terms agreed on a call. General information, not legal or security advice.