Practical Blockchain Security

Explore how blockchain architecture translates engineering choices into secure, scalable systems, from public, private, hybrid to consortium networks, with cryptography, consensus, and smart contract design.

Explore the post-merge Ethereum architecture, featuring the execution and consensus clients, the validator role, and the beacon chain coordinating shards, finality checkpoints, and validator attestations.

Discover Hyperledger Fabric as a modular, enterprise blockchain platform for consortium networks, featuring plug-and-play components, chaincode deployment, endorsement and ordering services, and flexible privacy and an API suite.

Flow architecture scales blockchain performance with sharding concepts, multi-node proof-of-stake, four-layer validation, acid transactions, and cadence smart contracts with vault-based asset handling.

Explore how blockchain bridges enable cross-chain data and asset transfers across networks. Learn about bridge types such as native, oracle, and liquidity networks, and evaluate security, cost, and interoperability trade-offs.

Genesis block starts every blockchain as the zero previous-hash anchor. It ties to block height, nonce, transaction data, and fees, and explains how mining and difficulty establish trust and consensus.

Walk through what's inside a block with a block explorer, from block height and genesis to UTC timestamps, 220 transactions, 89 transactions, and key concepts like gas, uncles, and nonce.

Explore consensus mechanisms beyond proof of work and proof of stake, including delegated proof of stake, proof of authority, proof of burn, and directed acyclic graphs (dags).

Explain the differences between hard and soft forks in blockchain networks, including how miners, developers, and full nodes influence consensus, and how SegWit and backward or forward compatibility shape upgrades.

Apply hashing to ensure data integrity in blockchain by generating fixed-length outputs that detect any changes and verify blocks with Merkle roots, previous hashes, and nonces.

Learn how timestamp servers, hashes, and digital signatures prove data existed at a specific time on the blockchain, using RC 3161 and ANSI ASC x995 standards.

Explore ethereum's peer-to-peer network, using a kamilla-based distributed hash table to discover local neighbors via udp, then secure communications over tcp, with hardcoded boot nodes and dev p2p rpcx considerations.

Explore front-end frameworks with a focus on React, a JavaScript library that manages state and renders dynamic pages through a component-based, declarative approach using the virtual DOM.

Explore vue.js, an open source front-end framework based on model view controller concepts for building single page and cross-platform apps with declarative rendering and reactivity.

Explore mapping OWASP top ten 2021 to blockchain systems, identifying broken access controls, cryptographic failures, injection, insecure design, and security misconfiguration in blockchain apps.

Explore wallet attack methods like phishing and dictionary attacks, and learn how entropy flaws and hot or cold wallet risks threaten user funds.

Explore peer-to-peer and distributed hash table security, highlighting routing vulnerabilities, bootstrap node manipulation, and data integrity risks in blockchain networks.

Explore partition attacks on blockchain networks, delaying Bitcoin block propagation via routing and unencrypted peer-to-peer traffic, risking double spends and network disruption.

Explore solo mining versus pools in proof-of-work networks, examining profitability, transaction fees, and renting power with solo pool options, honoring one computer, one vote.

Explain how cryptojacking and cryptomining malware secretly uses victims' resources to mine cryptocurrency in the background, balancing legitimate and illegitimate uses.

Explore how zero trust applies to blockchain, integrating identity management, risk assessment, and data. Use dashboards and analytics to monitor trusted nodes and endpoints in private or hybrid networks.

Explore how AWS managed blockchain enables Hyperledger fabric networks with version selection, member voting, invitations, and monitoring via CloudWatch and CloudTrail, plus detailed logging for security.

Discover how Ethereum on AWS via a managed blockchain enables quick node provisioning, JSON-RPC access, beacon chain queries, and built-in security with KMS and CloudWatch.

Explore how AWS QLDB merges database tech with ledger data to provide a cryptographically verifiable, append-only journal ledger with SQL-compatible particle query language and JSON support.

Compare third-party consensus cloud services with the Azure blockchain service, highlighting layer-based architecture, Ethereum and Hyperledger compatibility, and developer-focused, fully managed tools.

Discover how Hyperledger peers manage ledgers and smart contracts with the fabric gateway service. Learn how transaction proposals, endorsements, and the ordering process ensure secure, channel-based governance.

Explore iota's tangle as data sharing as a service, turning IoT data into a decentralized data lake with privacy modes, Merkle trees, and smart contracts.

Explore common threats and incidents in blockchain. Review real-world hacker cases on exchanges and defi, and learn security priorities for smart contracts and hot and cold wallets.

Understand aes, the de facto data-at-rest standard with 128-bit blocks and 256-bit keys. Learn how rounds, substitutions, and mixing secure encryption, and why side-channel attacks and best practices matter.