diff --git a/ch07.asciidoc b/ch07.asciidoc index 621c0989..51e0a63a 100644 --- a/ch07.asciidoc +++ b/ch07.asciidoc @@ -250,7 +250,7 @@ It is important to understand the limitations of transaction +nLocktime+. The on ==== Check Lock Time Verify (CLTV) -In December 2015, a new form of timelock was introduced to bitcoin as a soft-fork upgrade. Based on a specification in Bitcoin Improvement Proposal 65 (BIP-65), a new script operator _CHECKLOCKTIMEVERIFY_ (known also as _CLTV_) was added to the scripting language. +CLTV+ is a per-output timelock, rather than a per-transaction timelock as is the case with +nLocktime+. This allows for much greater flexibility in the way timelocks are applied. +((("Check Lock Time Verify (CLTV)", id="cltv07")))In December 2015, a new form of timelock was introduced to bitcoin as a soft-fork upgrade. Based on a specification in Bitcoin Improvement Proposal 65 (BIP-65), a new script operator _CHECKLOCKTIMEVERIFY_ (known also as _CLTV_) was added to the scripting language. +CLTV+ is a per-output timelock, rather than a per-transaction timelock as is the case with +nLocktime+. This allows for much greater flexibility in the way timelocks are applied. In simple terms, by adding the +CLTV+ opcode in the redeem script of an output it restricts the output, so that it can only be spent after the specified time has elapsed. @@ -298,7 +298,7 @@ After execution, if +CLTV+ is satisfied, the time-parameter that preceded it rem By using nLocktime in conjunction with +CLTV+, the scenario described in <> changes. Because Alice locked the UTXO itself, it is now impossible for either Bob or Alice to spend it before the 3-month locktime has expired. -By introducing timelock functionality directly in the scripting language, +CLTV+ allows us to develop some very interesting complex scripts. +By introducing timelock functionality directly in the scripting language, +CLTV+ allows us to develop some very interesting complex scripts.((("", startref="cltv07"))) The standard is defined in https://github.com/bitcoin/bips/blob/master/bip-0065.mediawiki[BIP-65 (CHECKLOCKTIMEVERIFY)].