v3 onion address

a v3 onion address is the modern 56-character .onion hostname derived directly from an ed25519 public key - self-authenticating and impossible to fake without the private key.

a version 3 onion address is the current format for .onion hostnames. technically it is nothing more than the service's ed25519 public key, a two-byte checksum and a version byte, all squashed into 56 base32 characters ending in d or q depending on encoding luck - which is why every v3 address is exactly 56 letters long.

because the address itself is the public key, the format is self-authenticating: connecting to the right address cryptographically guarantees you are talking to whoever holds the matching private key. no certificate authority, no dns, no registrar - the name is the identity.

the older v2 addresses (16 characters, based on rsa) were deprecated and then completely removed from the tor network in 2021. today any serious service publishes v3 only, and old 16-character links you still find floating around are dead ends or outright scams.

one consequence of key-derived addresses is vanity mining: since the key determines the address, you can generate key pairs until the prefix spells something nice. the catch is exponential math - each extra desired character multiplies the work by 32, so a six-letter prefix already means serious computing time. our vanity onion miner shows those honest odds before you start.