Point Time Locked Contract (PTLC)

A Point Time Locked Contract (PTLC) is a Bitcoin transaction which locks bitcoin to a point on Bitcoin’s elliptic curve. The outputs created by this transaction type are also time locked, meaning they cannot be spent before a certain time, as denominated in UTC time or block height. PTLCs are similar to Hashed Time Locked Contracts (HTLCs), but offer privacy gains as well as fee savings. For this reason, PTLCs may replace HTLCs as the driving contract behind the Lightning Network and other off-chain protocols.

Point Time Locked Contracts will become most accessible after Schnorr signatures have been implemented on Bitcoin, which will occur when the Taproot upgrade is activated.