Living without Trust- or -

The whats and wherefores of

blockchain

Dr. Gavin Wood (@gavofyork, founder Ethereum, Parity)

Operation

Operation

CONTENTION

AUTHORITY

The old model

The new model

Blockchain solves the issue of multiparty contention without having to involve a human.

Blockchain solves the issue of multiparty contention without having to involve a human.

Trust is no longer needed to contentiously interact with a third-party.

Blockchain solves the issue of multiparty contention without having to involve a human.

Trust is no longer needed to contentiously interact with a third-party.

This is the first ever instance of a technology which can do such a thing.

Blockchain solves the issue of multiparty contention without having to involve a human.

Trust is no longer needed to contentiously interact with a third-party.

This is the first ever instance of a technology which can do such a thing.

Practically speaking, we have just commoditized the rarest and most delicate of all intangible assets: trust.

What is the Blockchain?

A Blockchain is...

A Byzantine-Fault-Tolerant decentralised singleton fixed-function state-transition

system

It’s a type of Computing Machine

SlowCode runs 5-100x slower that natively compiled

Expensive to useBasic computation, memory and storage costs are ~1950s levels

Not always immediately decisive(Trans-)Actions can sometimes be reorganised

Sounds. Awesome.

Actually, it is.

A Shared SingletonOne single computer among many

Cannot Break, Shut down or be CorruptedResistant to attack or coercion

UbiquitousNo special or costly hardware required for access

Verifiable & AuditableAll transactions recorded, archived and replayable. Always.

So, Bitcoin?

And Ethereum?

And Smart Contracts?

So, Bitcoin would be...

Why?

Compared to connection-poor siloes

Innovation Turbocharger

Walled Gardens

Interoperability DifficultReliability, standards, trust, security collude to make it a nightmare

Increased BarriersFor integrating multi-party, multi-domain systems

CumbersomeServers are expensive to set up and maintain;

Blockchain always-on, always ready

Not to mention Security

AuditabilityAll results are readily auditable from their inputs

SecurityFewer servers and databases to hack

AuthenticityAll interactions are cryptographically signed:

Unauthorised Interactions are Impossible

Ethereum

Platform for Reduced-trust Computingfor

identity managementsmart contracts

interoperable infrastructurepermissions management

auditability

Permissioned vs Permissionless

FasterManaged upkeep

Private membershipTrusted

Legal

SlowerPublic ownershipOpen & transparentTrust-freeAllegal

PoW vs PoS vs PoA

SlowerWastefulHardwareNo-finalityTrust-freeProvenCostly

FastestEfficient

SoftwareFinality

Trust-boundSafeFree

FasterEfficientSoftware

Finality (Possible)

Trust-freeUnprovenLess costly

What is Polkadot?

What does it provide?

Pooled securityall constituent chains of our community guaranteed

Trust-free transactionsconstituent chains can send transactions to each other

How does it work?

Relay-chainthe top-level which coordinates consensus and

transaction delivery between constituents

Parachainsconstituent chains which gather and process

transactions

Basics of the Relay-chain

No functionalityno external transactions, no smart contracts

Fees leviedfees paid for voting/movement of tokens between

parachains

Polkadot’s Relay-chain ensures that transactions between the constituent parachains get delivered and that they are all operating correctly.

Parachains can take any form of globally-coherent consensus system; potentially even another relay-chain. Enterprise-friendly encrypted, private, proof-of-authority chains are supported.

Bridges can exist to ferry transactions between the relay chain and existing, independent chains like Ethereum.

Extensible, Scalable and Flexible

Open parachains can be tightly integrated into Polkadot, using Polkadot’s validators to ensure their correct operation. They are the easiest and cheapest form of integration.

Closed parachains can be weakly integrated into Polkadot, giving them the freedom to manage validation internally e.g. using a set of recognised authorities.

Bridged chains can be integrated into Polkadot too. Bridges add complexity and cost to integration, but allow the chain to exercise its own means of consensus.

Polkadot network

Consortium parachain (EWF)

Authorities manage parachain validation, access controls &c.

Transactions andinter-chain consensus

PolkadotConnected consensus

@gavofyork @polkadotproject @polkadotnetworkgithub.com/polkadot-io gitter.im/polkadot-io/Lobby