ZTDS Architecture Specification · 100% Local CPU Execution

Technical Security & Architecture

PrivacyScrubber enforces data confidentiality not through legal policy or backend promises, but through mathematical impossibility and local execution boundaries. All string scanning, Named Entity Recognition, regex parsing, and cryptographic tokenization occur strictly inside endpoint RAM.

< 1ms
Processing Latency

Zero network roundtrips

0 Bytes
Server Ingestion

Zero backend API endpoints

Volatile RAM
Ephemeral Memory

0 disk footprint / 0 database

25 Profiles
Sanitization Rules

Specialized industry parsers

Zero-Trust Data Sanitization (ZTDS) Lifecycle

How data flows exclusively within the local host security perimeter.

Zero-Trust Data Sanitization Architecture Lifecycle - 100% Client-Side Processing
Figure 1: The ZTDS execution model guarantees that plaintext PII is replaced with non-invertible surrogate tokens before dispatch to any cloud AI provider.
1. Ingest & Disambiguate

Raw inputs are evaluated locally in memory through our Contextual Entity Disambiguation Engine across 25 sector-specific compliance models.

2. Deterministic Mapping

Surrogate tokens (e.g. [NAME_1]) are deterministically assigned while preserving strict code, JSON, and table formatting integrity.

3. Ephemeral Rehydration

When the AI responds with sanitized tokens, 1-Click Reveal restores original values in sub-millisecond RAM execution, with zero disk trace.

Execution Isolation Across All 4 Surfaces

Detailed technical runtime boundaries for every deployment modality.

Web Workspace (In-Browser Single-Page App)

Web Worker Sandbox

Executes via an isolated HTML5 Web Worker thread detached from the main UI thread. Employs WASM-compiled Tesseract.js and PDF.js for local OCR. Network activity during scrubbing is physically blocked by Content Security Policy directives (connect-src 'none' for worker endpoints).

Chrome Extension (Manifest V3)

Target Tab Isolated World

Injected strictly into active target tabs (ChatGPT, Claude, Gemini) within an Isolated World context. The in-page shield HUD (Alt+Shift+X) intercepts the text area DOM node locally. Zero background page syncing or remote logging is executed.

PII MCP Server (@privacyscrubber/mcp-server)

Local Stdio / IPC Stream

Compliant with Model Context Protocol (Anthropic/Cursor). Communicates over local standard input/output (stdio) or loopback interface (127.0.0.1). Does not initialize HTTP listener ports, external sockets, or telemetry beacons.

Developer SDK (@privacyscrubber/sdk)

Deterministic Node/Browser Module

Isomorphic npm package with zero runtime telemetry dependencies. Functions execute synchronously on input strings. License validation is achieved via offline asymmetric cryptographic signature checks (Ed25519) without phone-home verification.

RAM Lifecycle & Cryptographic Primitives

Zero-persistence data destruction and authenticated session encryption.

Volatile RAM SessionMap Lifecycle

The mapping dictionary ([NAME_1] → "John Doe") is instantiated as an in-memory JavaScript Map object. It is strictly never committed to:

  • localStorage or sessionStorage
  • IndexedDB or WebSQL
  • HTTP Cookies or Service Worker caches

Upon tab closing, page refresh, or clicking "Reset Session", references are severed, immediately subjecting all memory allocations to browser V8 Garbage Collection zeroing.

TEAMS Session Encryption Primitives

When TEAMS users export an encrypted session bundle (.pssession) for team rehydration, cryptographic security is enforced via:

  • Symmetric Cipher:XChaCha20-Poly1305 (256-bit key, 192-bit nonce, AEAD authenticated).
  • Key Derivation:Argon2id (Memory-hard parameters: 64MB memory, 3 iterations, 4 parallelism).
  • Entropy Source:crypto.getRandomValues() Web Crypto API CSPRNG.

The 3-Step "Airplane Mode" Verification Playbook

Independent technical audit protocol for security engineers and SOC analysts.

Step 1: Open Workspace

Navigate to PrivacyScrubber in Chrome, Firefox, or Safari.

Step 2: Disconnect Network

Toggle your device to Airplane Mode or physically disconnect your Ethernet cable.

Step 3: Scrub & Inspect

Paste confidential text. Notice immediate sanitization with DevTools Network panel recording 0 requests.

DevTools Network Monitor (Simulated Capture) Active Egress Sniffer
POST /api/v1/scrub (Remote API)ERR_INTERNET_DISCONNECTED (0 bytes)
POST /telemetry/events (Telemetry)ERR_INTERNET_DISCONNECTED (0 bytes)
Local CPU Web Worker SandboxSTATUS 200 OK · 0.12ms Execution · 0 bytes Egress

Automated QA Suite & Empirical Security Benchmarks

Continuous Integration (CI) test assertions executed on every software build.

5.68 MB
JS Memory Heap

Budget: < 35 MB (Passed)

70.8 ms
DOM Mutation Scan

5,000 Live Nodes (Budget < 100ms)

236 ms
First Contentful Paint

Budget: < 1200ms (Passed)

0 Bytes
Network Egress

Zero prompt exfiltration

Automated CI Test SuiteTarget Threat VectorVerified Security AssertionCI Status
E2E UI & XSS Guard DOM-based XSS & Reverse Scrub Payload Injection HTML tags sanitized to textContent; zero JavaScript execution. 100% Passed
Extension Shadow DOM Isolation Host-Page DOM Traversal & Script Hijacking Closed Shadow Root (mode: "closed"); host scripts cannot access extension UI. 100% Passed
Tab Isolation & Memory Lifetime Cross-Tab Data Contamination & Storage Persistence 0 token leakage between parallel tabs; 100% memory zeroed on reload. 100% Passed
Extension Weak Vectors Guard Prototype Pollution & Cross-Frame Message Spoofing Rejects e.source !== window; postMessage prototype pollution mitigated. 100% Passed
Cross-Platform Crypto Handoff Cryptographic Desynchronization 100% AES-GCM / Argon2id bit-level interop across Web, Extension & MCP. 100% Passed
MCP Stdio JSON-RPC 2.0 Protocol Network Port Exposure in AI IDEs (Cursor/Claude) Air-gapped stdio transport only; zero listening network ports opened. 100% Passed