Consensus

Distributed Agreements

Consensus Mechanisms are sets of hard-coded rules(protocols) dictating the operational logic which enable a distributed/decentralized network of independent actors to operate uniformly without having to trust or even know each other.


The Byzantine Generals Problem

At the core of consensus mechanisms is an approach to an age old dilemma in computer science, the Byzantine Generals Problem (also known as the Byzantine Fault). The problem highlights difficulties in coordination and communication that decentralized systems have. When implemented and executed properly, decentralization provides higher security guarantees; however, when implemented and executed incorrectly can lead to disastrous outcomes.

Scenario: There is a powerful, evil kingdom {called Byzantium) with a population of 10,000 soldiers that is by protected high walls and rivers. One day, four (4) cities that have been abused by the evil kingdom, gathered to overthrow and end its tyranny. Each of the cities has 3,000 soldiers, if they surround the kingdom and attack all at once, they will overtake it; however should there be any problems or delays that cause just one of them to be late, early, or not present, then they will fail and forever lose their lives and the chance at having their freedom.

They configure a plan to all strike at dawn, and later that night, march to surround the kingdom. Once at their camps, each group is 10 miles away from each another. Each of the cities generals must confirm with one another before their attack. Their only way of doing to, is sending a messenger to relay the information.

Herein, we find the vey essence of the byzantine fault; the lack of any secure communication channels implies a multitude of potential threats and nuances including but not limited to: The messenger being captured by kingdom guards and divulging the message, the messenger being a rouge agent that either never makes it to other camps and returns with false information or spreads false information to the other generals, The messenger loses the message, time running out, etc.

The amount of things that can go wrong are endless, and the results... a matter of life and death. So then how do we enable secure communication?

This is the Byzantine Generals Problem.

The solution is a combination of pre-agreed upon protocol of actions-reactions based on the circumstances and methods of ensuring informational integrity {cryptography}; formally known as BFT.

BFT - Byzantine Fault Tolerance

BFT or Byzantine Fault Tolerance is a property of distributed systems that guarantees the ability to maintain uninterrupted operations in events of unanticipated disruptions within the network or from any of its individual components. Simply put, BFT is the module responsible for communication and security.

Faults in network can take place for a variety of facts; from natural latency issues caused by magnetic disruptions or hardware malfunction due to extreme weather conditions, to malicious entities shutting down serves or otherwise break the network.

BFT systems can continue to guarantee availability and consistency with a partition resistance of N=3f+1; meaning that a network can tolerate up to 1/3 of its node being corrupted.

Let N represent amount of nodes needed for a system to break. Let f represent the total amount of nodes

A system has 100 machines. If they ran a BFT system, how many machines can stop working and the network continue to operate?

N = (1/3*100) + 1 N = 33.333 + 1 The network breaks integrity when 34 of its nodes are faulty. *There cannot be "partial nodes" so the 34.33 must get rounded. As long as 67 nodes are operating, the system can guarantee integrity.

Absolutely all blockchain based projects have BFT, however, not all BFT modules are decentralized; in fact BFT is considered to be a centralized protocol. Blockchain Consensus mechanisms utilize a multitude of other interim protocols in addition to BFT, that handle adjacent elements.

For instance, Proof-Of-Stake is a very popular consensus mechanism used by the majority of crypto networks today. In Proof-Of-Stake it is commonly assumed that staked assets are what provides security; while that is true to an extent, it doesn't accurately portray the full picture. In Proof-Of-Stake, staked assets are used to combat sybil attacks and vote on the next block; meanwhile, there is a separate BFT engine running in the background simultaneously, making sure the node infrastructure is not being corrupted.


Considerations

In the thinking that led to the design of ATLETA, a multitude of varying mechanisms were considered, including POW (Proof-Of-Work) with different mining algorithms, the many variants of POS (Proof-Of-Stake), and even PoA (Proof-of-Authority).

PoW (Proof-Of-Work) solutions held high promises of decentralization and permissionlessness. However, the mechanical element quickly highlighted the pitfalls around needs to build customized ASICs machinery and a customized mining algorithm or opt for an existing mechanism and become subjected to influence of miners around the world that already have this equipment. Of course, this would have also imposed a great deal of operational complexity for ATLETA's userbase.

PoA (Proof-Of-Authority) was a non-starter from the beginning due to its blatant centralization. However, as some projects in the industry have been able to show, it is possible to build effective, highly adopted project even in those circumstances. While there were some obvious performance benefits, the lack of transparency and accountability was conflicting with the BCSports vision/mission. * Kudos to Binance and Chiliz for being able to pull this off, moving forward we anticipate there will be structural changes coming, be they architectural or business related, on the scale of what transpired with Binances leadership.

There are two tightly intertwined categories for which consensus mechanisms are responsible for, the economic and the technical. Both have a certain degree of operational overlap, as both are rooted in security, but ultimately, each serves their own distinct purposes.

The technical refers to the coordination of hardware and the economic refer to considerations for Sybil protection against spam/bot networks and social coordination around the native digital asset.


Consensus in ATLETA

After thorough evaluation, it became clear that in order to provide a truly credibly neutral, censorship resistant environment, the ATLETA Network must implement a modified version of POS (Proof-of-Stake) known as NPoS (Nominated Proof of Stake).

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