With this approach, block ciphers are used in the Cipher Block Chaining (CBC) mode in order to generate a MAC.
Any block cipher, for example AES in the CBC mode, can be used.
How Data Is Encrypted in Fixed-Size Chunks for Maximum Security (Part 2)
The MAC of the message is, in fact, the output of the last round of the CBC operation.
The length of the MAC output is the same as the block length of the block cipher used to generate the MAC.
MACs are verified simply by computing the MAC of the message and comparing it to the received MAC.
If they are the same, then the message integrity is confirmed; otherwise, the message is considered altered.
It should also be noted that MACs work like digital signatures, however they cannot provide non-repudiation service due to their symmetric nature.
Why This Matters for Blockchain Technology
Understanding MACs using block ciphers is not just an academic exercise — it has real-world implications for how blockchain systems are designed, deployed, and secured. Whether you are a developer building decentralized applications, a business leader evaluating blockchain adoption, or a curious learner exploring the technology, this knowledge provides a critical foundation.
Key Points to Remember
- MACs using block ciphers With this approach, block ciphers are used in the Cipher Block Chaining (CBC) mode in order to generate a MAC.
- Any block cipher, for example AES in the CBC mode, can be used.
- The MAC of the message is, in fact, the output of the last round of the CBC operation.
- The length of the MAC output is the same as the block length of the block cipher used to generate the MAC.
Conclusion
MACs using block ciphers represents one of the many innovative layers that make blockchain technology so powerful and transformative. As distributed systems continue to evolve, a solid understanding of these core concepts becomes increasingly valuable — not just for developers, but for anyone building, investing in, or working alongside blockchain-powered systems.
Whether you are just starting your blockchain journey or deepening existing expertise, mastering these fundamentals gives you the tools to think clearly about decentralized systems and make smarter decisions in this rapidly evolving space.