Backend Infrastructure for Sparrow Wallet Hosting

• Electrum Server: Use Electrs or Fulcrum to index Bitcoin Core and handle Electrum protocol queries.
• Bitcoin Full Node: Required to provide a complete blockchain to the Electrum server.
• Tor Hidden Service: Allows anonymous access to your Electrum server via .onion address.
• Sparrow Wallet: Runs on the client’s machine, connecting securely via Tor.

Multi-Tenant Hosting Platform

• Users can deploy isolated Electrum + Tor services.
• Charge monthly subscriptions and provide management dashboards.

System Architecture Overview

Base Layer

• Use cloud VPS or bare-metal servers.
• Containerize user stacks with Docker or Kubernetes.

Automation

• Provision with Ansible, Terraform, or Helm charts.
• Provide a backend (e.g. Django or Node.js) to manage deployments.

User Dashboard

• Display .onion address, status logs, and service health.

Download Verification Process

• Download software, checksums, and PGP signatures.
• Verify signatures using GPG and compare SHA256 hashes.
• Install only after verifying authenticity.

Download Sources & Verification

• Bitcoin Core: bitcoincore.org
• Sparrow Wallet: sparrowwallet.com
• Tor Project: torproject.org
• Electrs: github.com/romanz/electrs

Deployment Options

Option 1: Client Verifies & Uploads

• User downloads and verifies software locally.
• Uploads verified files to your platform.

Option 2: Server-Side Verification

• You verify software, users select and deploy verified builds.
• Publish your verification logs for transparency.

Hybrid Option

• Offer verification walkthroughs alongside automated deployment.

Compliance Considerations

• SOC 2: Recommended for SaaS credibility.
• HIPAA: Not applicable unless handling medical data.
• GDPR: Required if collecting EU user data.

Security Best Practices

Infrastructure

• Firewalls, SSH hardening, container isolation.
• Use immutable containers and resource quotas.

Access & Data

• 2FA for admin and user access.
• Encrypt all user data in transit and at rest.
• Do not store wallet keys or log Electrum traffic.

Monitoring & Backups

• Prometheus, Grafana, intrusion detection tools.
• Snapshot backups with encryption.