VeilNet vs TOR

What is Tor and How Does It Work #

Tor (The Onion Router) is an open-source, decentralized overlay network that enables anonymous communication over the internet. It was originally developed by the U.S. Naval Research Laboratory and is now maintained by the Tor Project, a non-profit organization. Tor’s core purpose is to protect users’ privacy and resist network surveillance and traffic analysis.

🌐 High-Level Functionality #

Tor hides the origin, destination, and content of internet traffic by routing it through a network of volunteer-operated relays. It achieves anonymity through a layered encryption technique called onion routing.

🧅 Onion Routing Explained #

1. Circuit Construction: When a user connects to the Tor network, their client software selects a random path through three Tor nodes:

   • Entry (Guard) Node

   • Middle (Relay) Node

   • Exit Node

2. Layered Encryption: The message is encrypted in layers — each layer corresponds to one of the three nodes in the path.

   • The outermost layer is decrypted by the entry node, revealing the address of the middle node.

   • The middle node decrypts the next layer, revealing the exit node.

   • The exit node decrypts the final layer, revealing the original data (unless further encrypted with TLS or HTTPS).

3. No Node Knows Everything:

   • The entry node knows the user but not the destination.

   • The middle node only sees encrypted data and the IPs of the entry and exit nodes.

   • The exit node sees the destination but not the source.

4. Circuit-Based Communication:

   • Tor uses fixed-length data units called cells to relay data.

   • Each circuit typically lasts for a few minutes before a new one is built.

5. Hidden Services:

   • Tor supports .onion addresses for servers that want to remain anonymous.

   • These hidden services allow users to host and access websites entirely within the Tor network, without revealing IP addresses.

Limitations and Challenges of Tor #

While Tor is a groundbreaking advancement in privacy-preserving networking, it has several critical limitations that impact its effectiveness under certain threat models:

🐢 1. Performance Bottlenecks #

• Low Throughput: Routing through three or more relays adds significant latency.

• Volunteer Infrastructure: Tor depends on bandwidth-constrained, community-operated relays, resulting in network congestion and slow speeds.

🔓 2. Exit Node Vulnerabilities #

• Unencrypted Data Exposure: Exit nodes can inspect traffic if the destination service doesn’t use HTTPS.

• Malicious Exit Nodes: Adversaries can operate exit nodes to eavesdrop or inject malicious content into traffic.

👁 3. Susceptibility to Traffic Correlation Attacks #

• A global passive adversary (e.g., state-level actor) observing traffic at both entry and exit points can use timing and volume analysis to correlate sender and recipient, breaking anonymity.

📡 4. Metadata Leakage #

• While content is encrypted, packet timing, size, and frequency are not fully obscured.

• Advanced statistical analysis can leak behavioral patterns or deanonymize users.

🔗 5. Limited Protocol Support #

• Tor only supports TCP traffic, which excludes latency-sensitive applications like VoIP, video calls, and real-time gaming that rely on UDP.

🏛 6. Centralized Directory Authority #

• Tor depends on a set of hard-coded Directory Authorities to manage and distribute the list of trusted relays.

• This creates a centralized trust bottleneck: if these authorities are compromised or coerced, the integrity of the network could be undermined.

• Additionally, all public relays are openly listed (IP, fingerprint, bandwidth), making them visible to adversaries for blocking, surveillance, or targeted attacks.