Skip to content
IAU Blockchainand IoT
TREN
Join

NOTES

Let’s understand first.

Short notes explaining blockchain and IoT in plain terms. Each starts with a summary, then the details.

Stuck on a term? Open the glossary
NOTE 014 min read[Author name]

What is blockchain?

SUMMARY

A blockchain is a ledger kept on many computers at once instead of in one place, and it is very hard to change after the fact.

A shared ledger

Picture a ledger. Normally a bank, an institution or a company keeps it, so trusting the records really means trusting that organisation. In a blockchain, copies of the same ledger live on many computers across a network. No one can alter a record alone, because the other copies immediately show the difference.

Why a “chain”?

Records are grouped into blocks. Each block contains a mathematical summary (a hash) of the block before it. Change an old block and its summary changes too, which invalidates every block that follows. That link is where the name comes from; quietly rewriting history becomes close to impossible.

How does the network agree?

The network decides whether a new block gets added using agreed rules, called a consensus mechanism. Bitcoin does this through mining with computing power (proof of work); Ethereum does it through value that participants lock up in the network (proof of stake).

Smart contracts

On some networks the ledger does more than store records: it also runs programs. These programs, called smart contracts, execute on their own once their conditions are met. One example is a payment being released automatically once “delivered” is written to the chain.

Is it needed everywhere?

No. Blockchain makes sense where you do not want trust concentrated in one organisation and where records must not change afterwards. When speed and privacy come first, an ordinary database is often the better choice.

Next note:What is the Internet of Things?
NOTE 024 min read[Author name]

What is the Internet of Things?

SUMMARY

The Internet of Things (IoT) is the idea that connected devices with sensors send what they measure somewhere, making the physical world observable and manageable.

A four-part system

Most IoT systems have four parts: sensors and actuators that measure or act, a communication layer that carries the data, a server or cloud that collects and processes it, and an application that shows the result.

A small example

A soil moisture sensor sends its reading wirelessly. The system sees that moisture has dropped below a set value and starts the irrigation. With no human involved, the loop of measure, decide and act is complete.

The brains of the devices

Inside many of these devices sits a small, low-power board such as an ESP32 or an Arduino. More capable boards like the Raspberry Pi are used to pre-process data in the field. These boards are also a natural starting point for student projects.

Communication options

Wi-Fi and Bluetooth suit short distances. Low-power wide-area networks such as LoRaWAN suit sensors that send little data from kilometres away. The choice comes down to a balance of range, power use and data volume.

The hard part

IoT’s biggest challenges are security, power consumption and data accuracy. A small device in the field is often poorly protected, and a sensor that measures wrongly leads to wrong decisions however well the system is built.

Next note:When blockchain meets IoT
NOTE 035 min read[Author name]

When blockchain meets IoT

SUMMARY

IoT produces data and blockchain makes it easier to show that the data was not changed afterwards. Traceability in food and agriculture is one of the most natural examples.

Who trusts the data?

If a sensor’s reading sits on one company’s server, whoever runs that server can change the record later. To prove that a product stayed at the right temperature throughout its journey, the record must not depend on any single party involved.

A shared ledger for records

Writing readings, or summaries of them, to a blockchain makes later tampering noticeable. Parties in a supply chain look at the same record and do not have to take each other’s word for it.

An important caveat

A blockchain only protects data that has been written; it does not guarantee that the sensor measured correctly. If a wrong reading is written to the chain, the wrong record becomes permanent. That is why device security and verifying measurements are part of the design too.

How it is done in practice

Writing every reading to the chain is slow and expensive, so usually a summary (hash) of the readings goes on the chain while the raw data is kept off-chain. If the data is altered later, the summary no longer matches.

Where it is used

Food and agricultural traceability, cold-chain monitoring, energy metering and supply chains are the most often mentioned areas. Our club’s Agro-Block project works in this intersection, in agriculture.

Back to top

It sticks better in conversation.

If you want to discuss these topics with the team and turn them into projects, the application is short.