Hide Tor use from the Internet Service Provider

Whonix ®

Download

Windows Linux Mac VirtualBox KVM Qubes USB ISO (coming soon) More options Source Code

About

Overview Features Whonix vs VPNs Why Open Source? Project Activities Contributors Mission & Vision

Docs

Documentation FAQ Troubleshooting

Community

Forums Contribute

Support

Self Support First Policy Search Engines, Docs and AI Support (Limited) Reporting Bugs Contact (Restricted)

Tools Upload file Special pages Recent changes Print Version Page meta What links here Related changes Page information

Page Read Edit History Move Protection Unwatch Watch Delete Purge

User Preferences Watchlist Contributions Logout Create account Login

Donate

• Network Obstacle
• Configure (Private) (Obfuscated) Tor Bridges
• Hide Tor use from the internet service provider (ISP)

Prevent the Internet Service Provider from discovering you are a Tor user.

It is impossible to Hide Tor use from the internet service provider (ISP). It has been concluded this goal is difficult beyond practicality.

See also Use of Tor Is Obvious.

This is a general issue. Anonymizing internet traffic is a hard problem that for example Tor and Whonix are working on. However, reliably hiding the type of any traffic (such as voice over IP or Tor) from the ISP in a threat model that includes endless data retention with retroactive policing is an even harder problem which is solved nowhere. This issue is unspecific to Whonix.

The technical discussion which lead to this conclusion can be found here. The former version of this wiki page documenting some of the challenges in hiding Tor use from the ISP is still available here.

As for hiding Whonix from network observers, this is a different subject which is covered on the Fingerprint page.

Technical Reasons

Using private and obfuscated bridges alone does not provide strong guarantees of hiding Tor use from the ISP. As Jacob Appelbaum has noted:

Some pluggable transports may seek to obfuscate traffic or to morph it. However, they do not claim to hide that you are using Tor in all cases but rather in very specific cases. An example threat model includes a DPI (deep package inspection) device with limited time to make a classification choice - so the hiding is very specific to functionality and generally does not take into account endless data retention with retroactive policing.

It is impossible to safely use a proxy to hide Tor. The connection between the user and the proxy is unencrypted and this applies to all proxies: http, https, socks4, socks4a and socks5. This means the ISP can still clearly see that connections are made to the Tor network. This fact is only mentioned here because proxies are constantly (falsely) suggested as a solution whenever this topic comes up in public arenas.

Using a VPN or SSH does not provide a strong guarantee of hiding Tor use from the ISP either. VPNs and SSHs are vulnerable to an attack called website traffic fingerprinting.

As Yawning Angel, founder and maintainer of the traffic obfuscator obfs4 pluggable noted:

Maintainer's rant

Honestly, it is possible to create a better obfuscation protocol than obfs4, and it's shelf-life expired years ago. No one should be using it for anything at this point, and no one should have been using it for anything for the past however many years since I first started telling people to stop using it.
People should also have listened when I told them repeatedly that there are massive issues in the protocol.

Do not ask me questions about this.
Do not use it in other projects.
Do not use it in anything new.
Use a prime order group instead of this nonsense especially if you are doing something new.

All I want is to be left alone.

At time of writing obfs4 is the only obfuscation protocol listed on bridges.torproject.org/options and there are no better alternatives available for traffic obfuscation, to hide the fact that a user is using Tor.

There is Snowflake (in Whonix wiki) but snowflake is not obfuscated.

Tor will make still certain network-related calls (like DNS lookups) even if DisableNetwork is set. Quote Tor man page (underline added):

DisableNetwork 0|1 When this option is set, we don’t listen for or accept any connections other than controller connections, and we close (and don’t reattempt) any outbound connections. Controllers sometimes use this option to avoid using the network until Tor is fully configured. Tor will make still certain network-related calls (like DNS lookups) as a part of its configuration process, even if DisableNetwork is set.

Footnotes

Whonix The most watertight privacy operating system in the world.

Dark mode

Follow us on social media

Supported by Power Up Privacy

Whonix is proudly supported until 2025 by Power Up Privacy, a privacy advocacy group that seeks to supercharge privacy projects with resources so they can complete their mission of making our world a better place. (Strictly subject to our sponsorship policy.)

At Whonix we value freedom and trust, supporting Open Source and Freedom Software

By using this website, you acknowledge you have read, understood, and agree to be bound by these agreements: Terms of Service, Privacy Policy, Cookie Policy, E-Sign Consent, DMCA, Imprint 2012- 2024 ENCRYPTED SUPPORT LP

Your support makes
all the difference!

We believe security software like Whonix needs to remain open source and independent. Would you help sustain and grow the project? Learn more about our 12 year success story and maybe DONATE!