Security Considerations

By using cryptography and consensus mechanisms, blockchains provide a secure and reliable way to share data and transactions without the need for a third party. However, we have to remember that "secure" does not mean "invulnerable."

51% attack

The primary and most common risk for a blockchain is the so-called 51% attack. It allows the attacker to potentially manipulate the blockchain’s ledger by reversing confirmed transactions, double-spending coins, and preventing new transactions from being confirmed. This attack is considered one of the most serious security threats for any blockchain because it can lead to a complete breakdown of the network’s trust and reliability. Despite the severity of the attack, its occurrence is fortunately quite rare.

A 51% attack is a type of attack that is specific to the blockchain platform. The most common goal of this attack is to successfully spend crypto twice (double-spending). But how can this happen?

Let’s look at a brief example for clarification. If a luxury watch shop accepts crypto payments (let’s say Bitcoin), an attacker could buy the watch and transfer 20 Bitcoin to the ...