Happy Families: new certificates for faster and easier relay management

by nickm | May 21, 2025

Relay Families are Tor’s way of grouping together relays run by the same operator, providing security and operational transparency. But the current 20-year-old design bloats directory info and becomes a maintenance headache as families grow. Tor 0.4.9 (currently in alpha) introduces cryptographic family certificates to help save up to 50% of the bandwidth cost for initial connections to the Tor network. Here's how it works, and what you can do to speed up the transition.