Anonymous Broadcasts: A Practical Guide

TL;DR

Sending truly anonymous broadcast messages is hard. This guide covers techniques to make it much harder for anyone to trace your message back to you, focusing on practical steps using Tor and mix networks. It’s not foolproof, but significantly improves privacy.

1. Understanding the Challenges

Broadcasting inherently makes anonymity difficult. When you send a message directly to many recipients, each recipient is a potential point of tracing back to you. Here’s why:

• Metadata: Even if the message content is encrypted, information about who sent it and when can leak.
• Recipient Cooperation: If enough recipients cooperate with authorities, they might be able to correlate timing or other details to identify you.
• Network Analysis: Your internet service provider (ISP) and others can observe traffic patterns that link your IP address to the broadcast.

2. Core Principles

We’ll use these principles:

• Obfuscation: Hide your identity and location.
• Mix Networks: Route messages through multiple intermediaries to break the link between sender and receiver.
• Decentralization: Avoid central points of failure or observation.

3. Setting up Tor

Tor is your first line of defense. It anonymizes your internet traffic by routing it through a network of volunteer-operated relays.

1. Download and Install: Get the official Tor Browser Bundle from https://www.torproject.org/download/
2. Verify Signature: Always verify the download signature to ensure you’re getting a legitimate copy. Instructions are on the Tor Project website.
3. Connect: Launch Tor Browser. It will automatically connect to the Tor network.
4. Check Your IP Address: Verify your apparent IP address has changed using a site like https://check.torproject.org/.

4. Using Mix Networks (e.g., Nym)

Mix networks add another layer of anonymity on top of Tor. Nym is a popular option.

1. Install the Nym Wallet: Download from https://www.nymproject.com/download/
2. Fund Your Wallet: You’ll need NYM tokens to send messages through the network. Purchase them on an exchange or obtain them via a faucet (be cautious with faucets).
3. Send Messages: Use the Nym wallet interface to compose and send your broadcast message. The network will route it through multiple mix nodes, obscuring its origin.

Example command using the Nym CLI:

nym send --recipient  --message "Your anonymous broadcast message"

5. Message Preparation

1. Encryption: Encrypt your message before sending it, even if the mix network provides some encryption. Use a strong encryption algorithm like AES-256.
2. Steganography (Optional): Hide your encrypted message within another file type (image, audio) to further obscure its presence. Be aware this is not foolproof and can be detected.
3. Avoid Identifiable Information: Do not include any personally identifiable information in the message itself or metadata.

6. Distribution

How you distribute the message matters.

• Decentralized Platforms: Use platforms designed for privacy, like secure messaging apps with end-to-end encryption and no logging (Signal, Session).
• Avoid Central Servers: Don’t rely on a single server or service to distribute the message.
• Multiple Channels: Distribute through several independent channels to increase resilience.

7. Operational Security (OpSec)

This is crucial! Your anonymity can be compromised by poor OpSec.

• Dedicated System: Use a dedicated computer solely for sending anonymous messages. Avoid using your everyday machine.
• Clean Operating System: Consider using a live operating system (Tails) that leaves no trace on the hard drive.
• VPN (Optional): While Tor is sufficient, a VPN before connecting to Tor can add an extra layer of obfuscation (but choose a trustworthy provider).
• Physical Security: Protect your computer from physical access.
• Timing Attacks: Be mindful of timing attacks. Avoid sending large bursts of messages at once, which could reveal your activity.

8. Limitations and Risks

No system is perfect.

• Network Surveillance: Sophisticated adversaries may still be able to correlate traffic patterns or deanonymize Tor nodes.
• Recipient Compromise: If recipients are compromised, your anonymity could be revealed.
• Mix Network Vulnerabilities: Mix networks themselves can have vulnerabilities.