SegWit (Segregated Witness)
Protocol● Common
A 2017 soft fork (BIP-141) that separates signature data ('witness') from transactions. Fixes transaction malleability, enables Lightning Network, and increases effective block capacity by ~1.7x. Native SegWit addresses start with bc1q.
Technical Notes
Witness data not counted in legacy block size limit. Weight = 3×base_size + total_size. Max weight: 4M WU ≈ ~2 MB actual. bc1q (P2WPKH) saves ~38% fees vs P2PKH. Activation via BIP-9 after UASF (BIP-148) pressure. Backwards compatible with old nodes.
Metadata
Visibility: Public
Created:1/3/2026by System