From Horse Carts to Cryptocurrency: The Irresistible Rise of Blockchain Mastery (Part 3)
Hashing Algorithm
A hashing algorithm is like a magic recipe that turns information (like a password) into a unique code. It's a one-way process, meaning you can't easily figure out the original information from the code. Think of it like a secret language only computers understand, helping keep information safe.
For example: In a hide-and-seek game, each friend has a unique hiding spot. They give each spot a special code based on something unique, like the number of nearby trees. When friends want to find them, they use the same rule, counting the number of trees near each hiding spot. The special code is kept secret to make it difficult for others to figure out where they are hiding. In the digital world, computers use more complex rules like hashing algorithms to create secure passwords.
The following are essential conditions for a good hash algorithm:
Deterministic:The hash output should always come from the same input. Consistency in the hashing process is guaranteed by this property.
Effective:A mathematically efficient algorithm should enable speedy data processing. For practical use in a variety of applications, this is significant.
Fixed Output Size: It should be the case that the hash function produces a fixed-size output irrespective of the size of the input data. This guarantees consistency in how various inputs are represented.
The Avalanche Effect: A significant variation in the hash output should result from even a small change in the input. This characteristic makes sure that even tiny changes to the input produce an entirely different hash value.
Collision Resistance:Two different inputs should not be able to produce the same hash output mathematically. It takes collision resistance to keep different data sections from having the same hash value.
Together, these specifications improve the security, dependability, and efficiency of a hashing algorithm across a range of uses, including data integrity checks, cryptographic protocols, and password storage.
For example, imagine you have a secret way to make your favorite pizza. Every time you follow the same steps, it tastes the same (deterministic). You're quick at making it (efficient), the pizza always has the same size (fixed output size), a small change in ingredients results in a big flavor difference (avalanche effect), and it's tough to make an identical pizza with a similar recipe (collision resistance). Similarly, a good hashing algorithm secures information in a way that's consistent, quick, uniform, sensitive to changes, and resistant to duplicates.
Immutable Ledger:
An immutable ledger is a type of record-keeping system where data is added and then permanently stored, making it resistant to interference or modifications.
For example, an immutable ledger is like using a special pen that makes permanent marks. Once information is recorded, it cannot be changed or tampered with. It ensures the integrity and security of the recorded data, making it trustworthy, much like a teacher using a pen that leaves an unalterable mark in a classroom attendance ledger.
Distributed P2P network
Imagine you and your friends want to keep a shared list of expenses for a trip. You can use a distributed P2P network, similar to a blockchain, to manage this. A distributed peer-to-peer (P2P) network on a blockchain is similar to a shared trip expense list. Everyone receives a copy of the list rather than having one person in charge, ensuring that no one person has complete control over the information. After adding an expense, it remains there forever and cannot be changed secretly. Since each person has a copy, this decentralized method increases security and is resistant to disruptions and losses. It provides scalability for additional participants, encourages trust among friends, and guarantees that everyone can contribute to the shared list. Like blockchain, it's an open, accessible global system where everyone works together to share information safely and transparently.
Byzantine Generals Problem
Imagine a city surrounded by a group of Byzantine generals, each in charge of an army division. They must choose between attacking and withdrawing and the only way they can speak to one another is by sending messengers. While some generals might be traitors, others might be faithful. The challenge lies in creating a plan that guarantees that all obedient generals arrive at a decision, even in the face of possible disinformation from betraying generals.
The problem of Byzantine generals:
• Communication difficulties: Generals can only communicate through messengers, who could be intercepted by traitorous generals.
• Consensus Requirement: Even if some of the loyal generals are traitors, they must all agree on whether to attack or withdraw.
• Traitor Resilience: The plan needs to be able to deal with false information from traitorous generals without making bad choices.
To solve the Byzantine Generals' Problem in computer networks and distributed systems, several algorithms, including the Byzantine Fault Tolerance (BFT) algorithms, have been developed. Even in a scenario where some nodes provide false or malicious information, these algorithms guarantee that consensus is reached.
Byzantine Fault Tolerance (BFT)
Byzantine Fault Tolerance (BFT) is a robust blockchain process in which military generals propose and vote on attacks, with consensus achieved when a supermajority agrees. This system adapts by identifying and isolating consistently faulty nodes, thereby ensuring the blockchain's integrity.
Consensus Protocol
Consider a group of friends planning a trip, with each representing a node in a consensus network. They must agree on a destination, and different consensus protocols represent various decision-making processes:
• Proof of Work (PoW): Friends solve puzzles to propose destinations, with the first successful one chosen.
• Proof of Stake (PoS): Friends vote based on their travel preferences, with the destination with the most support chosen.
• Delegated Proof of Stake (DPoS): A small group of friends propose and vote on the destination, with the most-voted option chosen.
• Practical Byzantine Fault Tolerance (PBFT): Friends engage in multiple rounds of voting, adjusting their choices based on others' preferences.
• Raft: Friends select a leader who suggests a destination, with the majority agreeing or a new leader elected.
• Proof of Authority (PoA): Trusted friends with more travel experience act as authorities, proposing and deciding on the destination.
• HoneyBadgerBFT: Friends collaboratively share preferences, ensuring agreement despite potential dishonesty.