Point Time-Locked Contracts (PTLCs) are a Bitcoin Lightning Network payment primitive that use elliptic-curve adaptor signatures and a single secret point, rather than a hash preimage, to enforce conditional, time-bound payment across a route. They replace Hash Time-Locked Contracts with a scheme that reveals no shared hash across hops, improving privacy and eliminating hash-linkage attacks between channels. PTLCs are enabled by Taproot’s Schnorr signatures and are proposed as a routing primitive for higher Bitcoin layers such as BTC Layer 3.