# Anti-censorship software

# Censorship

- Blacklist vs whitelist
- DPI
- Active inspection
- DDoS
- Legal and financial

# Centralized, Federated, Distributed

- Centralized < federated < distributed (P2P)
- More about this next monday

# Torrent

- P2P
- Trackers and DHT
- Legal issues (Europe): using, sharing, hosting 

# Torrent
![DHT](slides/censorship/dht.jpg)

# Blockchain

- Just P2P
- Decentralized ordering
- Financial censorship (Wikileaks, Autistici/Inventati, etc.)

# HTTP

- Web proxy
- HTTP proxy
- Signal

# SOCKS5 proxy

- Transport layer
- UDP ok
- SOCKS5h

# Hosting censorship

- DNS censorship (TPB,Autistici/Inventati)
- Hosting provider choice
- Crypto payment for Domain and Hosting
- Self-hosted

# Tor

- Created in 2002 by US Navy
- Low latancy
- Timing attack
- TCP only
- Hidden services (onion)
- Bridges
- Obfsv4

# Tor
![Tor](slides/censorship/tor.jpg)

# I2P

- Forked form Hyphanet (Freenet) in 2003
- High latency
- Timing attack resitant
- Better donors and origin
- It's own DNS (like Tor)
- Cant go outside of I2P network
- Torrenting is ok (special clients exist)
- Monero version

# I2P
![I2P](slides/censorship/i2p.jpg)

# VPNs

- Not as good as previous (longevity and privacy)
- DIY

# Proxychains

- Tor->I2P not allowed since July 2024
- Tor->SOCKS easy way to fix tor exit node issues