I was watching this two-month-old interview mostly for Justin Drake’s comments on quantum computing.
Starting at the time I linked, he says that AI making formal verification viable is a necessary precondition for shielded transfers on L1, which he is “excited about.”
We saw how Ethereum tried to catch up with Solana on L1 scaling. Will they try to do the same with Zcash on privacy?
I looked into it, and apparently this is part of the official roadmap (in the bottom right) and scheduled for the 2030s.
Vitalik has updated the official roadmap and tweeted to explain it.
In the tweet he says:
Privacy is no longer an afterthought, it is a first class goal. When designing Frames, the mempool, additions to the state tree, we explicitly ask the question “okay, how do quantum-safe, intermediary-free privacy protocol transactions go through this, and what is the overhead?”
and
Design of these new state types (current ideas: keyed nonces, ring buffers, UTXOs, statically accessible state, temp state) is an area where we will need a lot of feedback from application developers (incl. privacy-friendly application developers) and probably several rounds of rethinking and iteration.
It is notable that Ethereum is exploring UTXO-style state for some ERC20-like tokens, closer to the Bitcoin/Zcash model, perhaps because such a model is a more natural prerequisite for shielding.
The forum post Native UTXOs on Ethereum explains the motivation behind the move further.
This is also where the design pays off with respect to privacy. Because
recipientis just an address, it can be a stealth address, and because the spend is self-funded, that fresh address never has to hold ETH or appear astx.sender. The result is recipient unlinkability across payments. The sender is still exposed throughtopics[1], so sender privacy would need a separate mechanism such as mixing.
Apparently, the privacy considerations here relate more to short-term support for stealth addresses than to the longer-term goal of fully shielded transfers.