119 - CHECKTEMPLATEVERIFY
BIP: 119 Layer: Consensus (soft fork) Title: CHECKTEMPLATEVERIFY Author: Jeremy Rubin James O'Beirne Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0119 Status: Draft Type: Standards Track Created: 2020-01-06 License: BSD-3-Clause ==Abstract== This BIP proposes a new opcode, OP_CHECKTEMPLATEVERIFY, to be activated as a change to the semantics of OP_NOP4. The new opcode has applications for transaction congestion control and payment channel instantiation, among others, which are described in the Motivation section of this BIP. ==Summary== OP_CHECKTEMPLATEVERIFY uses opcode OP_NOP4 (0xb3) as a soft fork upgrade. OP_CHECKTEMPLATEVERIFY does the following: * There is at least one element on the stack, fail otherwise * The element on the stack is 32 bytes long, NOP otherwise * The DefaultCheckTemplateVerifyHash of the transaction at the current input index is equal to the element on the stack, fail otherwise The DefaultCheckTemplateVerifyHash commits...