IOTHACK Logs

Encrypting On-Chain Data, Tokenisation, Off-Chain Data Storage, and State Channel — together they answer "what data goes on-chain, in what form, and what stays off?" Storage on a blockchain is scarce (full replication), public (no privacy by default), and permanent (immutable). T...

Quiz: IOTHACK / Design Patterns for Blockchain Applications | updated: Sep 14, 2026

Throughput and latency get better as you move from permissionless → permissioned → central DB; the blockchains' cost buys tolerance of untrusted writers, which the central DB has zero of. Permissionless Permissioned Central DB Throughput Low High Very high Latency Slow...

Quiz: IOTHACK / Do You Need a Blockchain? | updated: Aug 26, 2026

Bitcoin sustains roughly 7 transactions/second (about 66 with security-preserving tweaks); Visa peaks above 50,000 — the gap is the price of decentralization. * Log scale: even with security-preserving tweaks Bitcoin stays three-plus orders of magnitude below Visa's peak — the t...

Quiz: IOTHACK / Do You Need a Blockchain? | updated: Aug 26, 2026

Oracle, Reverse Oracle, and Legal-and-Smart-Contract Pair — all bridge the gap between a sealed blockchain and the systems, data, and legal meaning that live outside it. Because a smart contract can't see beyond the chain, an application that has to react to real-world facts or p...

Quiz: IOTHACK / Design Patterns for Blockchain Applications | updated: Aug 26, 2026

One order-to-delivery flow uses every pattern: a credit check (pull-based inbound), a QR scan of a received package (push-based inbound), a back-office update (push-based outbound), and a buyer tracing the goods (pull-based outbound). * One order-to-delivery process uses all fou...

Quiz: IOTHACK / Blockchain Oracles: Bridging On- and Off-chain | updated: Aug 06, 2026

Transactions are hashed into a Merkle tree and only the root goes into the block header — so pruning old branches never changes the block's hash, letting nodes drop the data they no longer need. * Only the root hash sits in the block header; spent branches are stubbed off, so pr...

Quiz: IOTHACK / Bitcoin: A Peer-to-Peer Electronic Cash System | updated: Aug 01, 2026

Because e-voting's requirements pull against each other (anonymous votes vs public verifiability), and no proposed system has yet been shown to be simultaneously secure, verifiable, and private. E-voting genuinely matches the blockchain profile: many mutually distrusting parties,...

Quiz: IOTHACK / Do You Need a Blockchain? | updated: Jul 30, 2026

Because SCM's real weak point is the physical-to-digital interface: if you can't trust the humans/sensors entering data, the blockchain can't fix it; and if you can trust them, a shared database already suffices. Run SCM through the methodology: it stores state, has multiple writ...

Quiz: IOTHACK / Do You Need a Blockchain? | updated: Jul 30, 2026

None is universally best — each is the right answer for some application, and the choice must be made deliberately from trust assumptions, the parties involved, and performance needs. The take-away is anti-hype but not anti-blockchain. The authors provide a structured methodology...

Quiz: IOTHACK / Do You Need a Blockchain? | updated: Jul 30, 2026

Public verifiability, transparency, privacy, integrity, redundancy, and the trust anchor. Property What it means Public verifiability Anyone can verify the state was updated per the protocol Transparency How much of the data/update process observers can see (not all-or-n...

Quiz: IOTHACK / Do You Need a Blockchain? | updated: Jul 30, 2026