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Title: Can some one help explain OP_CSV and nSequence number? Post by: mandelduck on November 24, 2017, 05:22:07 PM Hi
I read about CSV and got totally confused by the who flag, nsequence number part of it so if you could help me on a few points id be much obliged! Say I want a utxo to be spendable after say 10 blocks so my script would be as so? OP_10 OPCSV OP_DROP 1.)what do I set nSequence to on the input? 2.) I have to worry about setting the nSequence value on the spend transaction inputs correct? Any sample code that anybody has would be helpful to see if anybody has it Thanks Title: Re: Can some one help explain OP_CSV and nSequence number? Post by: mandelduck on December 19, 2017, 06:10:43 AM Just to help anybody who may be having a similar issue I think I found the answer to my question
So there are two transactions in question, the first is the P2SH transaction containing the OP_CSV and the second is the spending transaction In the first transaction if you set an input script to 10 OP_CSV you are saying that you want the second spending transaction that uses this input (or output at this point) as a utxo to have an nSequence number the same or greater. In other words the stack will validate if your spending transactions inputs nSequence number is not less than the value (10 in this case) placed in the locking script Reference is here https://bitcoin.stackexchange.com/questions/45806/op-checksequenceverify-why-to-put-it-into-nsequence-field-if-it-is-already-into Furthermore the number (10 in this case) can be interpreted as number of blocks or as an actual timespan in seconds according to BIP68 https://github.com/bitcoin/bips/blob/master/bip-0068.mediawiki To me it seems to think of the nSequence number not as a single decimal number but as a list of bits, certain bits in this list of bits are used to represent the number you want to lock the time to, and other certain bits in this list of bits are more like switches that you turn on or off to change the interpretation of the number to number of blocks or timespan in seconds specifically if you think of your nSequence number as this binary number, the zeros towards the end can be set to represent the value, the 0 towards the middle can be set to change the interpretation and the zero at the end can be set to enable or disable any interpretation at all 0xxxxxxxx0xxxxxx0000000000000000 again more detail is in the official BIP68 anyway i'm sure I made some inaccuracies but thats my understanding so far |