VKontakte The Network Shell
Tezos enables its unique governance and self-amending capabilities through leveraging a network shell. To understand how the Network Shell works we need to break down a typical blockchain protocol into 3 primary and distinct sub-protocols. The Network Protocol The Transaction Protocol The Consensus Protocol
The network protocol is typically referred to as the “gossip” protocol and is how transactions are broadcast across the network between nodes. This protocol also includes downloading the blockchain , discovering peers, and broadcasting blocks to the network.
At the general protocol level, the network protocol usually consists of the most innovation and development activity.
The transaction protocol is defined by a cryptocurrency’s scripting language and in the case of Bitcoin is better known as the Unspent Transaction Output Model (UTXO).
Using Bitcoin as an example, this protocol consists of everything from the creation of Bitcoin during mining to the utilization of digital signatures for transaction verification. A fork of the transaction protocol is commonly referred to as a “soft fork”, and are usually not very contentious (at least compared to a hard fork).
The consensus protocol is probably the most significant as it articulates the model for reaching consensus of the state of the blockchain across all the nodes in the network. Bitcoin uses Proof of Work as its consensus model, however, Tezos uses an optimized form of Proof of Stake. This protocol is vital to the sustainability and authenticity of the blockchain as it prevents double-spending and makes the blockchain immutable. A fork of the consensus protocol is a “hard fork” and they are easily the most contentious.
Hard forks tend to divide cryptocurrency communities with more high-profile cases (Bitcoin/Bitcoin Cash) and is a problem that Tezos fundamentally aims to solve with its design.
The network shell of Tezos combines the transaction and consensus protocols into what they call the “blockchain protocol”. The blockchain protocol is effectively a consistent set of concurrent mutations to the global state of the blockchain where the blocks of the blockchain are defined as the operators acting on the state of the chain. Therefore, the blockchain protocol becomes introspective, allowing blocks to act on the protocol itself. This has important ramifications as it allows for the self-amending ability of the platform where stakeholders can vote directly on protocol upgrades to the system.
The network shell acts as an interface between the network protocol and the blockchain protocol (transaction and consensus protocols).
In doing so, it is the network shell’s responsibility to maintain the best chain known to the client. Tezos is written in OCaml and the network shell is capable of recognizing 3 objects. Blocks Transactions Protocols
Modules in OCaml can be used to directly mutate (amend) the existing protocol. Also, the network shell, importantly, functions as the deterrent of the network from DDoS attacks. The most prominent feature of the Tezos platform is the ability to implement protocols that are capable of amending themselves. This happens at the protocol level, but on the surface is popularly known as its on-chain governance feature.
Tezos Governance
The governance of the Tezos platform rests entirely with the stakeholders. All stakeholders have the ability to participate in the governance of the protocol and they vote on proposed protocol upgrades issued by developers who can attach invoices to their proposed upgrades for them to be compensated if their proposal is accepted.
While the initial voting mechanism is pre-defined, the governance process can even change the voting mechanism itself as the network progresses. There are many conditions that can trigger a protocol change, most notably a simple stakeholder vote.
However, much more complex triggers can be implemented through the governance process such as proving constitutionality of new amendments in regards to widely accepted amendments that are considered to be core tenets of the platform and voted as so by the stakeholders. Smart Contracts & Formal Verification
Another important feature of Tezos is its use of formal mathematical verifications of programs in order to prove their security while mitigating against prevalence of bugs in contract code.
The use of formal verification in conjunction with OCaml as the programming language is a refreshing improvement in smart contract logic, which has led to a number of hacks including the DAO exploit and Parity wallet hack. Proof of Stake Consensus & Baking
Tezos’ Proof of Stake implementation is an optimized combination of several concepts including Slasher, Chain of Activity, and Proof of Burn.
Rather than mining, Tezos uses what they refer to as “Baking”. In baking, block creation is performed by the stakeholders who, rather than performing PoW to solve a computationally difficult puzzle, obtain the right when a Tezos token (Tezzie) that they own is randomly selected to create a block.
Everyone is not required to participate in the baking process though, as it may seem from this model. Users who do not wish to participate can simply delegate their tokens to others for baking.
Bakers are warned a few weeks prior to when they need to actually bake, where they make the requisite token security deposit (known as a “bond), which is actually a dynamic deposit that changes based upon a number of blocks that a delegate is set to create. Twitter .
