Tor criticisms and alternatives for secure browsing

Introduction

Tor, known as The Onion Router, is a free, open-source network that routes internet traffic through a series of volunteer-operated relays to give users privacy and anonymity online. Called onion routing, this process hides a user’s IP address and browsing habits, which is why journalists, activists, whistleblowers, and people in censored regions rely on it. As of October 2024, Tor has approximately 1.95 million daily users worldwide, with heavy usage in countries like the United States (18.12% of users) (Statista, 2024). Even so, Tor has drawn real criticism, and some users have started looking elsewhere. The criticisms, the risk that governments or hackers control Tor nodes, and the alternatives for secure and anonymous browsing all deserve a closer look.

Criticisms of Tor

Association with illegal activities

Tor’s ability to host hidden services, accessible via .onion addresses, has led to its association with the dark web, where illegal activities such as drug trafficking, arms dealing, and distribution of child sexual abuse material occur. A 2013 study by Guitton analyzed 1,171 Tor hidden services and found that unethical content, such as illegal marketplaces, quantitatively and qualitatively overshadowed ethical content (ScienceDirect, 2013). However, a 2021 study noted that 38%-45% of hidden services contain illegal or unethical content, which suggests a significant but not dominant portion (MDPI, 2021). Legitimate users, including journalists and human rights organizations, rely on Tor for secure communication, as seen with platforms like ProPublica’s SecureDrop (ProPublica, 2016). Critics argue that Tor’s facilitation of illegal activities overshadows its benefits, though supporters emphasize its role in protecting free speech and privacy in oppressive regimes.

Security vulnerabilities

Tor’s design is not foolproof. If a malicious actor controls both the entry and exit nodes of a Tor circuit, they could perform traffic correlation attacks to deanonymize users. Research has identified vulnerabilities like circuit fingerprinting and eclipse attacks, which could compromise anonymity (MDPI, 2021). For example, in 2014, law enforcement seized Tor nodes, and there were suspicions they operated some to track users (Ars Technica, 2014). Tor also relies on a modified Firefox browser, and unpatched vulnerabilities in older versions could be exploited (Medium, 2017). The Tor Project mitigates these risks through regular updates and monitoring, but the potential for deanonymization remains a concern.

Performance issues

Tor’s multi-hop routing, which involves encrypting and relaying traffic through at least three nodes, results in slower browsing speeds compared to standard internet connections. This latency is most noticeable when streaming or loading complex sites, and it easily frustrates users (EXPERTE.com, 2022). A 2008 study highlighted performance challenges in low-bandwidth networks, and while improvements have been made, speed remains a trade-off for anonymity (MDPI, 2021).

Government ties and funding concerns

Tor’s origins trace back to the US Naval Research Laboratory in the mid-1990s, with funding from agencies like DARPA and the State Department. In 2013, US government funding accounted for approximately 63% of Tor’s budget (The Guardian, 2013). Critics, such as those cited in Surveillance Valley, argue that this reliance raises questions about Tor’s independence, and some speculate about potential backdoors ([Surveillance Valley, 2018]([invalid url, do not cite])). The Tor Project counters that its open-source code allows public auditing, and executive director Andrew Lewman has stated that Tor does not collaborate with agencies like the NSA to reveal user identities (Wikipedia, 2025). The controversy persists, as government funding is seen by some as a conflict of interest for a privacy-focused tool.

Risks of nodes hosted by governments or hackers

Potential threats

Tor’s decentralized structure allows anyone to operate a relay, including governments or malicious actors. If an entity controls both the entry and exit nodes of a circuit, they could correlate traffic to identify users or manipulate data, such as through man-in-the-middle (MitM) attacks. Exit nodes are the weak point. They decrypt traffic before it reaches its destination, which can expose unencrypted data (Reddit, 2015). Past incidents show the risk:

• In 2020, a group controlled over 23% of Tor’s exit nodes and used SSL stripping attacks to manipulate cryptocurrency transactions (ZDNet, 2020).
• The KAX17 group, active since 2017, operated hundreds of relays (peaking at over 900) by 2021, potentially for deanonymization, and controlled up to 16% of guard capacity and 35% of middle relays (The Record, 2022).

Mitigation efforts

The Tor Project has taken concrete steps to deal with malicious relays:

• Network Health Team: Established in 2020, this team monitors relay activity and develops criteria for identifying suspicious behavior, such as relays joining simultaneously without contact information (Tor Project, 2022).
• Removal Process: Suspicious relays are flagged or rejected by directory authorities, and removal takes majority agreement. For example, KAX17 relays were removed in November 2021 after detection (The Record, 2022).
• Community Reporting: Users and researchers, like nusenu, contribute to spotting malicious relays, and that work improves network security (Medium, 2021).
• Security Improvements: Tor Browser 11.5 introduced HTTPS-Only mode to reduce MitM risks, and ongoing funding supports new monitoring tools (Tor Project, 2022).

Despite these efforts, the open relay system still carries risk, and users should take extra precautions such as end-to-end encryption.

Alternatives to Tor

I2P (Invisible Internet Project)

I2P is a decentralized, peer-to-peer network focused on anonymous communication within its own ecosystem. Unlike Tor, which excels at accessing the clearnet anonymously, I2P is optimized for hidden services (eepsites) and uses unidirectional tunnels for stronger security. It is reportedly faster for internal services but less effective for regular web browsing due to limited outproxies (Cloudwards, 2025). I2P’s distributed network database contrasts with Tor’s centralized directory approach, so the network has fewer single points of failure (I2P, 2022).

Freenet

Freenet is a peer-to-peer platform for censorship-resistant publishing and data sharing. It handles static content well, so it is not a good fit for dynamic web browsing, but it works well for anonymous file sharing. Its decentralized structure reduces reliance on specific nodes, but it requires Java and has a steeper learning curve (Privacy Guides: Freenet).

Tails

Tails is a live operating system that runs from a USB drive and routes all internet traffic through Tor. It leaves no trace on the host computer, which makes it a good fit for sensitive tasks like whistleblowing. But it relies on Tor’s infrastructure, so it inherits Tor’s vulnerabilities (Fossbytes, 2017).

Virtual private networks (VPNs)

VPNs encrypt traffic and route it through a single server, which hides the user’s IP from websites and ISPs. Unlike Tor, VPNs require trust in the provider, as they can see user traffic. They are faster than Tor but offer less anonymity due to single-hop routing. Reputable VPNs like Mullvad or ProtonVPN are popular choices (Privacyend, 2024).

Privacy-focused browsers

Browsers like Brave and Mullvad Browser prioritize privacy by blocking trackers and ads. Brave is open-source and integrates cryptocurrency features, while Mullvad Browser, developed by the VPN provider, focuses on anti-fingerprinting. Neither provides Tor’s level of anonymity, as they do not use multi-hop routing (AlternativeTo, 2025).

Conclusion

Millions of people still rely on Tor for anonymous communication, especially in censored regions. However, its association with illegal activities, security vulnerabilities, performance issues, and government funding concerns have fueled criticism. Malicious nodes remain a real risk even with the Tor Project’s efforts, so users should be cautious: use HTTPS and avoid logging into personal accounts. Alternatives like I2P, Freenet, Tails, VPNs, and privacy-focused browsers each have their own strengths and limits. Users should choose based on their specific needs: Tor for clearnet anonymity, I2P for hidden services, or VPNs for faster privacy. Combining tools, such as using a VPN with Tor, can improve security further. Privacy is still a live issue, and ongoing improvements plus community vigilance will keep shaping these tools.