Session 01
Fundamentals

DISTRIBUTED
LEDGERS.

The architectural shift from centralized databases to trustless, decentralized networks.

Core Objective

Deconstruct the anatomy of a blockchain: cryptographic hashing, the immutable chain structure, and the consensus mechanisms that enable trust without authority.

01

The Ledger Shift

A distributed ledger is a database that is consensually shared and synchronized across multiple sites, institutions, or geographies.

No Single Point of Failure
Consensus-Based Updates
Audit via Transparency
1.0
INTERACTIVE MESH NETWORK

FIG 1.0: Node Synchronization

02

System Properties

Decentralization

State sovereignty is distributed; no admin access.

Consensus

Mathematical agreement on the "truth" of the ledger.

Transparency

Read-access is typically open to all observers.

Trustlessness

Reliance on cryptography, not human reputation.

03

Chain Architecture

A blockchain is a specialized distributed ledger where data is batched into blocks and linked cryptographically.

3.1

FIG 3.1: Immutable Chain Structure

Block Header Data

Immutability Guarantee

Changing a single bit in Block N invalidates the hash, breaking links to Block N+1 and all subsequent blocks.

04

Cryptographic Primitives

SHA-256 Hashing

A one-way function that maps input data of arbitrary size to a fixed-size bit string (digest).

Input: "Hello"Output: 185f8...
Input: "hello"Output: 2cf24...

// Avalanche Effect Observed

Merkle Trees

A binary hash tree allowing efficient verification of content in large data structures.

4.2
Click data blocks (cubes) to verify hash path

FIG 4.2: Merkle Root Construction

Public / Permissionless

  • Open Access (Bitcoin, Ethereum)
  • Censorship Resistant
  • High Redundancy

Private / Permissioned

  • Restricted Access (Hyperledger)
  • Identity Known
  • Higher Throughput

System Check

Ledgers are distributed, not centralized

Hashing ensures data integrity & immutability

Consensus replaces central authority