CortexVault

# CortexVault

### Your Second Brain. Only You Can Open It.

## The Problem

Your notes contain your most valuable thoughts — business strategies, legal cases, medical records, research breakthroughs, personal journals.

**Yet every note-taking app asks you to trust a server.**

- Notion? Your data lives on their servers.

- Evernote? They can read your notes.

- Obsidian? Great, but your vault sits unencrypted on disk.

One breach. One subpoena. One careless employee. And your private thoughts become public record.

---

## The Solution

**CortexVault encrypts everything. Locally. Before it ever touches your disk.**

```

Your Password

     ↓

  Argon2id (64MB memory, 3 iterations)

     ↓

  256-bit Master Key (lives only in RAM)

     ↓

  AES-256-GCM per note (unique nonce every save)

     ↓

  .vault files on disk (indistinguishable from random noise)

```

No server. No account. No telemetry. No network requests. **Ever.**

When you lock your vault, the master key is cryptographically erased from memory using `zeroize`. Not freed — **zeroed**. There is no recovery. There is no backdoor.

---

## Who Is This For?

| Professional | Use Case |

|---|---|

| **Lawyers** | Case notes, client communications, litigation strategy |

| **Doctors** | Patient observations, differential diagnoses, research notes |

| **Journalists** | Source identities, investigation notes, unpublished findings |

| **Researchers** | Pre-publication data, grant proposals, peer review notes |

| **Executives** | M&A planning, board discussions, competitive intelligence |

| **Everyone** | Diaries, passwords, financial planning, anything private |

If your notes could damage you, your clients, or your sources — **they should be encrypted**.

---

## Features

### Core (Free)

- **Military-grade encryption** — AES-256-GCM + Argon2id. The same algorithms protecting classified government data.

- **Markdown editor** — Write in Markdown with live preview. Split-pane editing.

- **`[[Wiki-links]]`** — Link notes together. Build your knowledge graph.

- **Auto-save** — Changes saved automatically. Never lose work.

- **Keyboard-first** — `Ctrl+N` new note, `Ctrl+S` save, `Ctrl+L` lock, `Ctrl+K` search.

- **Zero network** — No internet connection required. No data leaves your machine.

- **Bilingual UI** — English and Traditional Chinese interface.

### Pro ($5)

- **Full-text search** — Instantly search across all encrypted notes. Results ranked by relevance.

- **Knowledge graph** — Visualize connections between notes. See how your ideas link together.

- **Markdown export** — Export decrypted notes to `.md` files.

- **Auto-lock timer** — Automatically lock vault after inactivity.

- **Password change** — Update your master password without re-creating the vault.

---

## Security Architecture

### What we do right

| Layer | Implementation |

|---|---|

| Key Derivation | Argon2id — 64MB memory, 3 iterations, 4 lanes. Resistant to GPU/ASIC attacks. |

| Encryption | AES-256-GCM — Authenticated encryption. Tamper detection built-in. |

| Nonce Management | Fresh 12-byte random nonce per write. No nonce reuse. |

| Memory Safety | Rust backend. No buffer overflows. No use-after-free. |

| Key Lifecycle | `zeroize` + `ZeroizeOnDrop`. Keys erased when vault locks. |

| File Integrity | Atomic writes (write-to-temp-then-rename). No half-written files. |

| Search Index | In-memory only (Tantivy). Never written to disk unencrypted. |

| IPC Boundary | Tauri command whitelist. Frontend can only call registered functions. |

| CSP | Strict Content Security Policy. No external resource loading. |

### What we don't do

- We don't phone home.

- We don't collect analytics.

- We don't have accounts.

- We don't store your password.

- We don't have a "forgot password" feature. **Because we can't.**

---

## Technical Stack

```

┌─────────────────────────────────────┐

│         React + TypeScript          │  ← UI Layer

│     Zustand · MDEditor · D3.js      │

├─────────────────────────────────────┤

│            Tauri v2 IPC             │  ← Bridge

├─────────────────────────────────────┤

│              Rust Core              │  ← Security Layer

│  argon2 · aes-gcm · tantivy · rand │

│         zeroize · walkdir           │

└─────────────────────────────────────┘

         Your filesystem only.

         No cloud. No server.

```

---

## Pricing

| | Free | Pro |

|---|---|---|

| Encrypted note storage | ✓ | ✓ |

| Markdown editor + preview | ✓ | ✓ |

| Wiki-links | ✓ | ✓ |

| Auto-save | ✓ | ✓ |

| Bilingual UI | ✓ | ✓ |

| Full-text search | — | ✓ |

| Knowledge graph | — | ✓ |

| Markdown export | — | ✓ |

| Auto-lock timer | — | ✓ |

| Password change | — | ✓ |

| **Price** | **$0** | **$5 one-time** |

No subscription. No recurring fees. Pay once, own forever.

---

## Install

Download `CortexVault_0.1.0_x64-setup.exe` and run it.

No account required. No internet required. Just a password you won't forget.

> **Warning**: There is no password recovery. If you forget your password, your data is gone. This is a feature, not a bug.

---

## Support

- **Sponsor**: [Ko-fi](https://ko-fi.com/ogodwin10)

- **Contact**: jmes100010@gmail.com