Port the ability for directory authorities to manage authority keys
Each directory authority has a “directory signing key.” Directory authorities use this key to provide a signed list of all the known relays to clients using the network. This means that unless an adversary can control a majority of the directory authorities, they can't trick a client into using other Tor relays.
This Activity includes developing ways for directory authorities to generate and manage signing and identity keys, to store keys in an encrypted way, to consume authority signing keys and certificates, and to alert when keys and certificates are close to expiration.