While several techniques have been proposed to speed up payments in permissionless blockchains, no current solution is entirely satisfactory for application scenarios like retail shopping. In particular, existing solutions like payment channels require users to lock up significant funds, while other schemes that rely on pre-defined validators do not protect users’ privacy during payment processing. In this paper, we define a new notion of second-layer privacy, which hides transaction details from off-chain validators and thus prevents targeted attacks on second-layer payment systems such as payment blocking (e.g., censorship) or off-chain user tracking. We then set forth to develop Quicksilver, the first second-layer payment scheme that is practical, fast, and provides second-layer privacy and censorship-resilience. We implement and evaluate Quicksilver for EVM-compatible chains and show that it effectively enables fast and private payments on popular blockchain platforms.