Collision immune successor for v3
Currently tor takes the onion-adresses have a fixed length. This makes them by definition susceptible to collision attacks fixed length means a finite number of results, while the amount of potential public keys is by design infinite. For onion-adresses it is as far as I know not a requirement to have a specific length, so we could theoretically sacrifice fixed adress length for collision immunity.
An example of how this could be done(very insecure) would be to generate a long random public key without a private key and have operators of onion encrypt their public key with it and use that as their onion-adress and all the other information put in a adress in th1 first n characters.