This deck explains the purpose, architecture, security model, and deployment considerations for Trezor Bridge. It is written for engineers, product managers and security reviewers who need a clear, practical overview of how Bridge enables secure host-device communication for Trezor hardware wallets.
Slide 1: Title + elevator pitch. Use for opening and agenda preview.
Problem: Secure host ↔ hardware communication
Context
Modern desktop and web applications need a reliable channel to communicate with USB hardware wallets. Browsers and OS restrictions make direct access inconsistent; drivers and native apps add friction. We need a cross-platform solution that is secure, user-friendly, and compatible with web applications.
Why it matters
- Users must sign transactions offline without exposing private keys.
- Phishing or compromised host software should not be able to exfiltrate secrets through a weak transport.
- Developers need a predictable API across Windows, macOS, and Linux.
Slide 2: Define the core problem and constraints.
What is Trezor Bridge?
Definition
Trezor Bridge is a lightweight local service that runs on a user's machine and mediates communication between web apps (or desktop wallets) and Trezor devices. It provides a standardized API, abstracts USB/transport differences, and isolates device traffic from untrusted processes.
Core capabilities
- Device discovery and session management
- Message serialization and transport routing
- Cross-origin-safe local endpoints for web apps
Use this slide to introduce Bridge to non-specialists.
Architecture overview
Components
Local Bridge Service
Runs as a background application, exposes a local HTTP(S) endpoint and handles USB device connections.
Client Apps
Web apps use the Bridge endpoint via CORS-safe requests. Desktop apps use local APIs to issue commands to the device.
Flow (simplified)
- App sends request → Bridge local endpoint.
- Bridge translates request → USB transport to device.
- Device responds → Bridge returns response to app.
Show architecture diagram if available. This slide summarizes key components.
Security model
Principles
- Minimal trust in host software — private keys never leave the device.
- Strong session isolation and origin checks for web clients.
- Transport-level protections and explicit user confirmation for sensitive actions.
Attacks considered
Bridge defends against malicious web pages, compromised desktop apps, and man-in-the-middle attempts on the local host. The device firmware and UI remain the ultimate authority for approving transactions.
Slide 5: emphasize that user confirmation on the device is the primary safeguard.
Developer API & UX
Simple HTTP-based API
Bridge exposes JSON endpoints that map to device actions: get public keys, sign transactions, enumerate devices. Client libraries wrap these calls for convenience.
Best practices
- Always show device fingerprint and transaction summary to users.
- Use session timeouts and re-authentication for long-lived sessions.
- Fail gracefully if Bridge is not installed — provide clear install flow.
Developers: include code examples and link SDK docs in presenter notes.
Deployment & compatibility
Platforms
Bridge supports Windows, macOS, and Linux. Distributions include installers and portable versions for varied environments.
Browser & App integration
Works with modern browsers through local HTTP endpoints and with native apps using IPC or local socket interfaces.
Slide 7: mention update cadence and signed installers as operational notes.
Operational & privacy considerations
Logging & telemetry
Bridge should minimize logs and avoid storing sensitive request/response payloads. Any telemetry must be opt-in and privacy-preserving.
Upgrades & integrity
Use signed releases and in-app update checks. Provide clear rollback steps in release notes to mitigate bad updates.
Slide 8: good place for runbook bullets and maintenance checklist.
Demo & user flows
Example flows
- First-time install → device pairing → confirm firmware fingerprint
- Sign a transaction: app builds tx → Bridge forwards → device prompts user → signed tx returned
- Recovery flow: explicit user steps on device with strong prompts
Tip: during demo, emphasize the device screen as the security boundary — users must examine and approve every transaction on-device.
Slide 9: run a short live demo or recorded walk-through.
Summary & Resources
Key takeaways
- Trezor Bridge provides a cross-platform, secure transport between hosts and Trezor devices.
- Device-side confirmation remains the strongest protection — design user flows accordingly.
- Keep Bridge minimal, privacy-preserving, and well-documented for developers.
Resources
Official site: trezor.io
Office & PowerPoint: office.com
Slide 10: final summary, Q&A prompt, links to docs and installers.