P2WSH: Native SegWit Multisig

P2WSH (Pay-to-Witness-Script-Hash) is the most efficient and secure way to implement collaborative custody (multisig) on the Bitcoin network today. It removes the need for P2SH wrappers and utilizes the full 32-byte security of the SHA256 algorithm.

1. Maximum Fee Discount

P2WSH is the "Holy Grail" of fee efficiency for multisig users.

• In a 3-of-5 multisig setup, you have 5 public keys and 3 signatures.

• By moving all this data to the Witness Area, P2WSH applies the 75% discount to the largest part of your transaction.

• For complex organizational wallets, switching from Legacy to P2WSH can reduce fees by over 50%.

2. Advanced Security

As we discussed in the P2SH-P2WSH module, native SegWit multisig uses 32-byte (256-bit) hashes.

• This makes it physically impossible to craft a "Collision" where two different scripts result in the same address.

• It represents a significant upgrade over the 20-byte (160-bit) hashes used by legacy P2SH addresses.

3. The bc1q... Address

P2WSH addresses look very similar to P2WPKH addresses, but they are significantly longer.

• P2WPKH: 42 characters.

• P2WSH: 62 characters. This extra length is due to the 32-byte hash (vs 20-byte), providing a clear visual signal that the address belongs to a complex script rather than a single key.

4. The Standard for Modern Custody

From hardware wallet multisig setups to Lightning Network channels, P2WSH is the engine that powers modern Bitcoin scripting. It is clean, efficient, and highly secure.

Feature	Legacy P2SH	Native P2WSH
Address Prefix	3	bc1q
Hash Length	20 Bytes	32 Bytes
Fee Discount	0%	75% (Witness Area)
Collision Resistance	High	Extreme

In the next section, we will analyze the ScriptPubKey Structure of P2WSH.