Bech32 Encoding: The SegWit Standard

With the activation of Segregated Witness (SegWit), Bitcoin moved away from the legacy Base58 format to a more modern, efficient standard called Bech32 (BIP173). It is the encoding that powers all addresses starting with bc1.

1. Why a new standard?

Base58 served Bitcoin well for years, but it had several technical drawbacks:

• Case Sensitivity: Mixing upper and lowercase made it harder to dictate addresses over the phone.

• QR Code Bloat: Base58 is inefficient for QR codes, requiring larger, more complex squares.

• Slow Math: The "Successive Division" used in Base58 is computationally expensive for large payloads.

2. The Native SegWit Look

Bech32 addresses are long and lowercase. Example: bc1qar0srr7xfkvy5l643lydnw9re59gtzzwf5mdq3 While they look longer than legacy addresses, they are actually More Efficient for the network to process and cheaper for you to spend from.

3. The Components of Bech32

Every Bech32 string is composed of three distinct parts:

1. HRP (Human-Readable Part): Tells you which network you are on (bc for Mainnet).

2. Separator: The number 1. This is always present and tells the computer where the data begins.

3. Data Part: The encoded information, including the Witness Version, the Hash, and the Checksum.

4. Total Case Insensitivity

Bech32 is defined as Case Insensitive. While standard usage is lowercase, an address in ALL CAPS is mathematically identical. This makes it impossible to make a mistake by accidentally hitting the Caps Lock key.

Feature	Base58	Bech32
Address Prefix	1 or 3	bc1
Case Sensitive?	Yes	No
QR Efficiency	Medium	High
Error Detection	Hash-based	Polynomial-based

In the next section, we will analyze the Base32 Alphabet used in this standard.