SegWit, Taproot, and modern signing

Understand the upgrades that made modern Bitcoin protocols practical.

Follow these 9 lessons in order, or choose the topic you need. Each lesson combines an explanation, a worked example and practice inside the Guild.

1. SegWit architecture

   SegWit separates witness data, fixes third-party malleability, changes weight accounting, and enables safer second-layer commitments.

   35 minutes · Open lesson

2. Taproot outputs

   P2TR commits to an internal key optionally tweaked by a script-tree root, presenting one compact output key on chain.

   45 minutes · Open lesson

3. Key-path spending

   The internal key holder can authorize a spend with a tweaked Schnorr signature without revealing alternative scripts.

   55 minutes · Open lesson

4. Tapscript

   Script-path spends reveal one leaf, its witness, and a control block while keeping unused branches private.

   65 minutes · Open lesson

5. Taptrees and control blocks

   Merkle paths prove that a revealed leaf was committed into the Taproot output key.

   35 minutes · Open lesson

6. Unspendable internal keys

   Protocols can use a provably unspendable internal key to require script-path enforcement rather than retaining a hidden bypass.

   45 minutes · Open lesson

7. MuSig and key aggregation

   Interactive multisignature schemes aggregate public keys and signatures while defending against rogue-key attacks.

   55 minutes · Open lesson

8. FROST

   Flexible Round-Optimized Schnorr Threshold signing coordinates nonce commitments and signature shares from a threshold subset.

   65 minutes · Open lesson

9. Covenant proposals

   CTV, APO, CAT-related designs, and other proposals trade expressiveness, analyzability, and deployment risk.

   35 minutes · Open lesson