Tor Network Deep Dive

🧅 What is Tor?

Tor (The Onion Router) is free, open-source software that enables anonymous communication by routing internet traffic through a worldwide volunteer network of thousands of relay servers. It protects users from network surveillance and traffic analysis.

Why Tor Matters for DrugHub Marketplace:

• IP Address Protection: Hides your real IP address from websites, preventing identification
• ISP Monitoring Prevention: Your internet provider cannot see which websites you visit (only that you're using Tor)
• Hidden Services Access: DrugHub operates as a .onion hidden service, only accessible through Tor
• Location Privacy: Makes it extremely difficult to determine your physical location
• Censorship Resistance: Allows access to blocked services in censored regions

🔄 How Tor Works: Onion Routing

Tor uses a technique called "onion routing" where your internet traffic is encrypted in multiple layers (like an onion) and routed through three random relay servers before reaching its destination.

The Three-Hop Circuit:

1. Entry Node (Guard): The first relay that knows your real IP address but doesn't know what you're accessing. Your computer maintains consistent guard nodes for months for security reasons.
2. Middle Node: Knows neither your IP nor your destination. Simply passes encrypted traffic between entry and exit nodes.
3. Exit Node: Decrypts the final layer and connects to the destination website. Knows what you're accessing but not your real IP address.

Encryption Layers:

Each hop removes one layer of encryption:

• Your Computer → Entry Node: Triple-encrypted (Exit key + Middle key + Entry key)
• Entry Node → Middle Node: Double-encrypted (Exit key + Middle key)
• Middle Node → Exit Node: Single-encrypted (Exit key)
• Exit Node → Destination: Depends on destination's HTTPS support

🌐 Hidden Services (.onion Sites)

Hidden services like DrugHub marketplace operate entirely within the Tor network, providing anonymity for both operators and users. Unlike normal websites, .onion sites are only accessible via Tor and provide mutual anonymity.

How Hidden Services Work:

• No Exit Node: Traffic never leaves the Tor network, providing end-to-end encryption and anonymity
• Location Hidden: The server's physical location and IP address remain hidden
• Rendezvous Point: Client and server meet at a randomly selected relay, neither knowing the other's identity
• Cryptographic Addressing: The .onion address is derived from the service's public key, preventing impersonation

Hidden Service Connection Process:

1. Hidden service publishes its existence to Tor directory servers
2. Your Tor Browser queries directory servers for the service's introduction points
3. You send a message to an introduction point requesting a connection
4. Service and client agree on a random relay as a rendezvous point
5. Both parties build circuits to the rendezvous point and communicate

📱 Tor Browser: Your Gateway to Anonymity

Tor Browser is a modified version of Firefox pre-configured for anonymous browsing. It includes several privacy enhancements beyond routing traffic through Tor.

Download & Verification:

Official Source: https://www.torproject.org/download/

CRITICAL: Always verify PGP signatures of downloads. Malicious copies of Tor Browser have been distributed via fake websites.

Privacy Features Built Into Tor Browser:

• NoScript: Blocks JavaScript by default (configurable)
• HTTPS Everywhere: Forces HTTPS connections when available
• No Browser Fingerprinting: Standardizes browser characteristics to prevent identification
• No Tracking: Blocks trackers, deletes cookies on close
• Circuit Isolation: Different sites use different Tor circuits
• Automatic Updates: Ensures you have latest security patches

Security Levels:

🌉 Bridges: Bypassing Censorship

In some countries, ISPs and governments block access to the Tor network by blacklisting known Tor entry nodes. Bridges are unlisted Tor entry nodes that help you connect even when Tor is blocked.

When to Use Bridges:

• Your ISP blocks Tor connections
• You're in a country that censors Tor (China, Iran, etc.)
• You want to hide Tor usage from your ISP (though VPN is better for this)
• University/workplace network blocks Tor

Types of Bridges:

• obfs4: Most popular. Makes Tor traffic look like random noise (recommended)
• meek: Routes traffic through cloud services (Amazon, Azure). Slower but harder to block
• Snowflake: Uses ephemeral proxies. Good for anti-censorship, less for anonymity
• Standard: Regular bridges without obfuscation. Rarely sufficient against censorship

How to Get Bridges:

1. Built-in bridges: Tor Browser → Settings → Tor → "Select a Built-In Bridge"
2. Request bridges: Email bridges@torproject.org from Gmail/Riseup/Yahoo
3. BridgeDB: Visit https://bridges.torproject.org/

🔬 Advanced Tor Concepts

Circuit Isolation

Tor Browser automatically uses different circuits for different domains, preventing sites from linking your activities. Each website gets its own three-hop path through the Tor network.

Manual Circuit Control: Click the onion icon in address bar → "New Circuit for this Site" to get a fresh path if experiencing issues.

Guard Nodes

Your Tor client uses the same entry guards for 2-3 months. This seems counterintuitive but actually improves security by limiting the chances of using a malicious entry node.

Why this matters: If guards changed frequently, over time you'd inevitably use a malicious one. Fixed guards reduce this probability.

Tor Over VPN vs VPN Over Tor

Tor Network Attacks & Defenses

• Timing Attacks: Global passive adversaries might correlate entry and exit traffic. Defense: Tor's encryption and routing make this extremely difficult.
• Malicious Exit Nodes: Can intercept unencrypted traffic. Defense: Use HTTPS everywhere, use .onion sites when possible.
• Browser Exploits: JavaScript vulnerabilities can deanonymize users. Defense: Use "Safest" security level, never enable JavaScript on untrusted sites.
• Confirmation Attacks: If attacker controls entry and exit, they might confirm you accessed a site. Defense: Use VPN + Tor, use .onion hidden services.

⚙️ Configuration Best Practices

Recommended Tor Browser Settings for DrugHub Marketplace:

Additional OPSEC for Marketplace Operations:

• Use VPN + Tor combination (VPN first, then Tor)
• Never access personal accounts in same Tor session
• Use Tails OS for maximum security and anti-forensics
• Create fresh Tor circuit between different marketplace activities
• Never login to marketplace from home network without VPN
• Verify DrugHub .onion address through multiple trusted sources
• Enable bridge if you want to hide Tor usage from ISP (or use VPN)

🔍 Verifying Tor Connectivity

Check if Tor is Working:

1. Tor Check: Visit check.torproject.org
   Should say: "Congratulations. This browser is configured to use Tor."
2. IP Check: Visit any IP checker - should show Tor exit node IP, not your real IP
3. DNS Leak Test: Visit dnsleaktest.com - should show Tor exit node, not your ISP's DNS

Testing .onion Access:

Try accessing these test hidden services:

• DuckDuckGo: https://duckduckgogg42xjoc72x3sjasowoarfbgcmvfimaftt6twagswzczad.onion/
• Facebook: https://facebookwkhpilnemxj7asaniu7vnjjbiltxjqhye3mhbshg7kx5tfyd.onion/
• ProtonMail: https://protonmailrmez3lotccipshtkleegetolb73fuirgj7r4o4vfu7ozyd.onion/

If these load, your Tor Browser can access hidden services including DrugHub marketplace.

⚠️ Common Tor Misconceptions

🚀 Getting Started with Tor for DrugHub Marketplace

Step-by-Step Setup:

1. Download Tor Browser from official source: torproject.org/download
2. Verify PGP signature (instructions on Tor Project website)
3. Install and Launch Tor Browser
4. Configure Security: Settings → Privacy & Security → Security Level → Safest
5. Optional: Configure Bridge if in censored region or using VPN
6. Test Connection: Visit check.torproject.org
7. Access DrugHub Marketplace using verified .onion address
8. Verify .onion Address via PGP-signed marketplace announcements

📖 Related Guides

💡 Quick Troubleshooting

Common Tor issues and how to fix them.

Tor Won't Connect

First, check if Tor is blocked in your region. Try using bridges (obfs4 recommended). If that doesn't work, try a VPN before Tor. Some ISPs throttle or block Tor traffic.

Hidden Service Not Loading

Hidden services like DrugHub can be slow or temporarily unavailable. Wait 30-60 seconds for initial load. If still failing, request a new circuit. The service might be experiencing DDoS or maintenance downtime.

Connection Drops Frequently

Unstable connections usually indicate network issues. Try a different guard node by restarting Tor Browser. If using VPN + Tor, try a different VPN server. Some VPNs interfere with Tor traffic.

Getting Captcha Loops

Some clearnet sites detect Tor exit nodes and present endless captchas. Either use a different exit (new circuit) or access via VPN for those specific sites. For .onion services like DrugHub, this isn't an issue since exit nodes aren't used for hidden services.

✅ Tor Security Checklist for DrugHub

Run through this checklist before every DrugHub Market session. Missing even one step can compromise your security. Build these habits until they become automatic. Security is not a one-time setup but an ongoing practice. Each session requires attention to detail.

🔗 External Resources

• Official Tor Project Website
• Tor Project Support
• Tor Browser Manual
• Tor Community Forum