Pluggable Transports — Censorship Circumvention

When ISPs block known Tor guard addresses or fingerprint Tor TLS handshakes, pluggable transports wrap traffic in shapes that appear as random bytes or HTTPS to major CDNs. This article compares transports referenced in DrugHub connectivity notes.

obfs4

obfs4 obfuscates byte patterns between client and bridge. It is the default recommendation when guard IP lists are blocked but generic HTTPS is allowed. Bridges are unlisted; obtain lines from bridges.torproject.org or trusted distributors.

snowflake

snowflake routes through ephemeral WebRTC proxies operated by volunteers. Useful when bridge IPs are burned quickly. Higher latency than obfs4 but resilient against static blocklists.

meek-azure

meek tunnels through CDN-front domains (Azure). Suitable for corporate networks that whitelist major cloud HTTPS endpoints only. Often the slowest option but sometimes the only viable path.

Selection guide