Blockchain Technology

This lesson introduces students to blockchain technology through the themes of trust, record integrity, and responsibility in digital systems. It is designed for secondary Computer Science / Informatics classes and builds from conceptual foundations to technical mechanisms and critical evaluation.

Students begin with a recap of risks in AI and cyber-physical systems, then move into the core problem of how digital decisions and records can be trusted over long periods of time. A realistic scenario involving AI-based job application decisions is used to motivate the need for tamper-resistant records and to anchor the purpose of blockchain.

The lesson develops a clear, student-friendly explanation of blockchain as a shared digital ledger built from linked blocks. Key technical mechanisms are taught step by step, including hashing as a data fingerprint, Proof of Work as a cost-based protection mechanism, and distributed ledgers as a safeguard against single-party control. Each concept is reinforced with hinge questions, short applied tasks, and model answers so the slide deck works both for classroom teaching and independent revision.

Students then examine limitations and risks, including energy consumption, 51% attacks, irreversibility of errors, and the difference between anonymity and pseudonymity. Real-world use cases such as cryptocurrencies, school records, land registers, and financial transactions are evaluated with advantages and constraints.

The resource is fully self-contained and explicitly sequenced, with recap tasks, diagnostic questions, consolidation activities, and model answers throughout. It is suitable for a 45–90 minute lesson and fits well within units on AI, data integrity, and future technologies.