Ethereum P2SH Address Decoding: A Step-by-Step Guide
As a developer, understanding how to work with Ethereum addresses is crucial for building decentralized applications on the blockchain. One of the most complex concepts in Ethereum is the P2SH (Public Key Hash) address scheme used by the Ethereum network.
In this article, we will delve into the process of decoding a P2SH address using its associated hexadecimal script (hex.script). We’ll go through an example transaction and break it down step by step to help you understand how it’s decoded.
What is a P2SH address?
A P2SH address is a type of Ethereum address that uses a Public Key Hash (PKH) as its key, rather than a private key. This means that the address is not directly linked to an individual wallet account, but instead is a digital signature that verifies the sender’s identity.
The Process of Decoding a P2SH Address
To decode a P2SH address, you need to know two things:
- The hexadecimal script (
hex.script): This represents the public key hash of the sender’s private key.
- The
scriptSigandscriptHash: These are the two components of the hexadecimal script that contain additional information about the transaction.
Example: tx bea1e7ae7ecdc502215717f30d62a12085bb2866d8db730dfb626b60c337534c
Let’s take a look at an example transaction tx bea1e7ae7ecdc502215717f30d62a12085bb2866d8db730dfb626b60c337534c. The hex script for this transaction is:
1 0x... ( PKH of the sender's private key )
In this example, PKH stands for Public Key Hash.
Decoding the P2SH Address
To decode the P2SH address, we need to combine the hex.script, scriptSig, and scriptHash. Here’s what they look like:
tx bea1e7ae7ecdc502215717f30d62a12085bb2866d8db730dfb626b60c337534c
The hex.script is 0x..., which represents the PKH of the sender’s private key.
ScriptSig and ScriptHash
Let’s break down each component:
- ScriptSig: This is the first four bytes (
0x00 01) that contain a signature for the transaction. In this case, it’s an empty signature.
- ScriptHash: This is the last two bytes (
0x8c 01) that contain a hash of the transaction data.
Decoded P2SH Address
Combining these components, we get:
tx bea1e7ae7ecdc502215717f30d62a12085bb2866d8db730dfb626b60c337534c
This is the decoded P2SH address 0x..., which represents a digital signature.
Example Use Case
To verify the authenticity of a transaction, you can use this decoded address to create a public key hash of the sender’s private key. Then, you can use the resulting PKH as the hex.script for any other transaction that uses P2SH addresses.
By understanding how to decode P2SH addresses using their associated hexadecimal script and the scriptSig and scriptHash, you’ll be well on your way to building robust and secure decentralized applications on the Ethereum network.