Wanseob Lim, the founder of Ethereum 9¾, released the implementation of the Ethereum privacy layer Zkopru on the Ethereum technology forum ethresear.ch. This is a two-layer expansion solution that uses zk-SNARK and optimistic rollup to achieve private transactions. It supports the second-layer network Realize the privacy transfer and privacy atomic exchange between ETH, ERC20, ERC721 at low cost. In addition, with the prepayment function, users can withdraw assets from the second layer before final confirmation. Each private transaction based on the Ethereum blockchain consumes 8800 gas. When the gas limit is 11.95M and the block time is 13.2s, the maximum TPS is 105.