Snowflake

P2P Infrastructure

A pluggable transport for the Tor network that uses ephemeral volunteer browser proxies to help censored users circumvent internet blocks. Volunteers run lightweight WebRTC proxies (via browser extension, webpage tab, or standalone binary) that relay traffic to a Tor bridge, disguising the connection as ordinary WebRTC video/voice traffic.

Comunidade

Links

Visitar Comunidade

Detalhes

Licença

BSD-3-Clause (https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake)

Status de Dev 🟢 Ativo

Detalhe do Status de Dev

Released (production)

Proprietário

Tor Project, Inc. / Originally created by Serene (hacker / former Google engineer)

País

USA

Ano de Início 2016

Stack

Go (snowflake client + standalone proxy); JavaScript (browser proxy extension); WebRTC (data channels for P2P traffic)

Financiamento

OTF (Open Technology Fund) — funded Snowstorm (Rust rewrite, 2023); Tor Project general funding; volunteer-operated bridges raise funds via Open Collective

Última Investigação 9 de mar. de 2026

Domínios de Caso de Uso

Platform Evolution & Sovereignty

Capacidades

Self-hostable

P2P Infrastructure Atributos

Origins

Flashproxy (predecessor, deprecated); uProxy (Google Ideas/Jigsaw, 2013-2016) — Snowflake evolved the ephemeral proxy concept with WebRTC + automatic NAT traversal

Database

N/A (transport relay, no data store)

Data Formats

Arbitrary (application-agnostic transport; disguised as WebRTC data channel)

Mobile Support

N/A (volunteer proxy infrastructure)

Web Support

Yes (browser extension for Firefox and Chrome)

Native Apps

Yes (standalone binary for Linux/macOS/Windows; gomobile for Android)

Terms

Free (volunteer bandwidth donation; no compensation to proxy operators)

Funds

OTF grant (amount undisclosed); Open Collective community donations for bridge operating costs

Based On

Flashproxy (ephemerality concept); WebRTC (P2P transport); domain fronting (broker rendezvous via CDN)

P2P Architecture

Ephemeral WebRTC peer-to-peer proxy mesh; domain fronting for broker signaling

Overlay Network

Global broker-mediated (clients matched to available proxies via centralized broker using domain fronting; traffic flows P2P)

Content Addressing

Local-First

N/A (routing infrastructure, not storage)

E2EE

Yes — traffic encrypted by Tor's onion encryption layers; WebRTC DTLS for transport

Byzantine Fault Tolerance

Signature

TLS (DTLS for WebRTC transport); Tor circuit encryption layers

Permissions

N/A (open relay; no access control — any censored user matched by broker)

Protocol Maturity / Standardization

Community Standard (Tor pluggable transport v2.1 spec; open specification, active community development)

Infrastructure Function

Censorship circumvention; Relay / proxy

Threat Model

State-level censorship; DPI (Deep Packet Inspection); ISP-level blocking; IP enumeration blocking

Volunteer / Node Model

Volunteer-operated (browser extension or tab); Embedded (runs on user device while browser is open)

Traffic Visibility

No content (encrypted payload only); Partial metadata — proxy sees client IP and Tor bridge destination but not content or final destination

Active Deployment Scale

~140,000 unique proxy IP addresses concurrently (2024); ~35,000 daily users connecting via Snowflake; ~29 TB daily traffic relayed