Ethereum: How OP_EQUALVERIFY works in a standard transaction?

Understanding Ethereum’s OpEquals Protocol: A Guide to OP_EQUALVERIFY

In the world of blockchain technology, several protocols have emerged to enable secure and efficient transactions between parties. One such protocol is
Ethereum, specifically its
OpEqualVerify (OP_EQUALVERIFY) feature. In this article, we’ll delve deeper into how OP_EQUALVERIFY works in a standard Ethereum transaction.

What is OpEqualVerify?

OpEqualVerify is a cryptographic technique developed by Vitalik Buterin, the co-founder of Ethereum. It is used to verify that two transactions are equal and come from the same origin, without relying on digital signatures or other forms of authentication. Essentially, OP_EQUALVERIFY ensures that each transaction is isolated and follows a predetermined set of rules.

Public Key Hashing Basics

Before we get into OpEqualVerify, it’s essential to understand how public key hashing works in blockchain transactions. A
public key hash (PKH) is a digital fingerprint created from a user’s
private key. It is calculated using the following steps:

• The private key is converted into an
  encrypted message

  .

• This encrypted message is hashed using a cryptographic algorithm, such as SHA-256 or Keccak-256.

• The hash value is then stored in the public key.

OP_EQUALVERIFY: How it Works

Now, let’s apply this understanding to OpEqualVerify. Here’s a step-by-step explanation:

• Transaction Creation

  

  : Two parties (e.g., sender and recipient) create a new transaction on the Ethereum network.

• Each transaction includes two hash values: transactionHash and expectedHash. These are used as input parameters for the OpEqualVerify process.

• The
  public key hash of the sender’s private key is calculated, along with transactionHash.

• A hash function (e.g., SHA-256) is applied to the hash values ​​of the public key and transactionHash.

• If the resulting hash value matches an expected hash value for a given block height, the transaction is verified as
  equal.

How ​​does OP_EQUALVERIFY verify the transaction?

To verify that two transactions are equal, the following conditions must be met:

• The same public key hash exists in both transactions.

• The transactionHash values ​​in both transactions match.

• A valid signature (using a private key) is present for each transaction.

If these conditions are met, OpEqualVerify verifies that the two transactions originated from the same account and are equal according to the expected rules. If any of these conditions are not met, the transaction will be rejected by Ethereum’s validation layer.

Example Use Case

Let’s say we want to verify that a user sent 100 Ether (ETH) from one address (0x1234567890abcdef) to another address (0x8765432109876543210abcdef). We create two transactions, tx1 and tx2, with the same public key hash (0x8765432109876543210abcdef) for the sender’s private key.

We then calculate the OP_EQUALVERIFY hashes using the following inputs:

• tx1Hash: The hash value of a block containing tx1

• expectedHash1: A specific expected hash value (e.g. 0x123456789012345678901234567890abcdef)

• tx2Hash: The hash value of a block containing tx2

If the resulting hashes match, we have successfully verified that tx1 and tx2 are equal. If not, the transactions will be rejected.

Conclusion

In conclusion, OP_EQUALVERIFY is a crucial protocol in Ethereum that ensures the integrity and uniqueness of transactions. By understanding how it works, you can better understand the basic mechanics of blockchain technology. Remember to always verify transaction hashes using OpEqualVerify before proceeding with any transaction on the Ethereum network.