INTRODUCTION

A block chain is a like a public ledger but with encrypted copies distributed among nodes in a network. The main premise is there is no need for a central database. An entry in one copy is distributed to all other node block chain entries.

Attempting to change a ledger entry using a blockchain network is not impossible but difficult. You must alter the entire ledger on 51 per cent of all network nodes. If the ledgers are not simultaneously altered, the nodes detect the entry as illegal and prevent the change.

What makes it even more difficult is that blockchains are both encrypted and hashed, each entry or group of entries chained to the previous segment in the block.

So, what is the main benefit using blockchains? On the blockchain, all transactions contain metadata with a unique entry identifier which acts as a proxy for the ‘owner’ making them private. Access to an entry is governed by permissions that may use single, multi-factor authentication along with digital signatures that are unique to a device or a service.

Because no central command exists, nobody has the authority or access to facilitate reading and by design, changing an entry. The methods used, and there are many variants to a blockchain structure, are too detailed to provide here.

The following are links on the subject. Click on the PDF icons

BlockChain Introduction

UbiVault Fabric

 

 

Smart Contracts

Smart Contracts

INTRODUCTION - Smart Contract is a term defining one or more computer program instructions that automatically execute and optionally enforce performance of an agreement (contract) using blockchain technology. Terrms of the smart contract are recorded in a computer language as a set of instructions.

Smart contracts (also called self-executing contracts, blockchain contracts, or digital contracts) are simply computer programs that act as agreements where the terms of the agreement can be preprogrammed with the ability to self-execute and self-enforce itself.

The main goal of a smart contract is to enable two anonymous parties to trade and do business with each other, usually over the internet, without the need for a middleman.

Smart contracts, often created by computer programmers through the help of smart contract development tools, are entirely digital and written using programming code languages such as C++, Go, Python, Java.

This code defines the rules and consequences in the same way that a traditional legal document would, stating the obligations, benefits and penalties which may be due to either party in various different circumstances. This code can then be automatically executed by a distributed ledger system

In the context of blockchains and cryptocurrencies, smart contracts are:

A simple way to see it work is how CoinDesk describes the process:

Blockchains can run code. While the first blockchains performed a small set of operations as transactions of a currency-like token, newer blockchains can support complex operations using programming languages.
The program itself is recorded on the blockchain, which gives it permanence and censorship resistance. The program can control blockchain assets – and also store and transfer amounts of cryptocurrency. Being part of a blockchain, it will always execute as written and no one can interfere or modify its operation.

The following are links on the subject. Click on the title next to icons

Smart Contracts

Great Chain of Numbers

Privacy coins - how to protect owners

Hawk Model for Smart Contracts