Weighing Transactions, The Witness Discount
summary
Walks through raw Bitcoin transaction serialization, shows the first spent Taproot input and the serialized difference between legacy and SegWit: marker/flag, zero-length scriptSig, then the witness stack. Explains txid comes from the stripped transaction so legacy and SegWit nodes share IDs, and full witness data is witness committed via coinbase. Defines weight as 4x non-witness + 1x witness with a 4,000,000 limit, cites a 2.77 MB block and discusses the debated witness-discount removal.
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chapters (11)
- 0:00Introduction
- 1:03Transaction serialization basics
- 9:43Native SegWit and Taproot outputs
- 12:23First Taproot transaction
- 13:47SegWit transaction structure
- 18:38Block size limits and weight units
- 21:32Transaction IDs and commitments
- 25:53Calculating transaction weight
- 28:24Removing the witness discount
- 31:36Witness discount incentives
- 32:17Comparing transaction sizes
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