Practical MCU crypto: Turning security theory into firmware you can run

Security is no longer a “nice-to-have” reserved for high-end products. Even small embedded designs — from sensor nodes to DIY controllers — are now expected to support encryption, secure storage, and protected communications. The problem is that many engineers (and plenty of makers) understand cryptography in theory, but struggle to turn that knowledge into working microcontroller code.

Practical Microcontroller Cryptography (Elektor 2026), by Dogan Ibrahim and Ahmet Ibrahim, is written to close that gap. Rather than focusing purely on abstract mathematics, the book builds a bridge between core cryptographic concepts and real implementations on widely used microcontroller platforms.

Cryptography you can compile, flash, and test

The book’s approach is deliberately hands-on. You don’t just learn what algorithms are supposed to do. You see how encryption, hashing, and key handling behave when implemented on resource-constrained targets. That includes the realities that embedded developers face every day: limited RAM, limited Flash, and tight performance budgets.

To make the learning process concrete, many examples are implemented as complete working programs for popular boards such as the Arduino Uno and the Raspberry Pi Pico, allowing you to run, modify, and experiment with the code directly.

Classical ciphers as practical teaching tools

Instead of treating classical ciphers as historical trivia, the authors use them as a practical entry point into cryptographic thinking. You work through a broad range of well-known methods, including: Spartan Scytale, Atbash, Caesar, ROT13, Alberti Disk, Vigenère, Affine, Polybius, Playfair, Beaufort, Ottoman Codebook, and One-Time Pad.

Importantly, the book also demonstrates how many of these ciphers can be attacked. You learn not only how they work, but why modern systems require stronger approaches.

Random numbers, DES, AES

Modern cryptography depends heavily on randomness and efficient symmetric encryption. The book explains how to implement both pseudo-random and true random number generators on microcontrollers, and why the quality of randomness directly affects security.

Symmetric encryption is covered with working implementations of DES and AES, including AES-128 and AES-256. The authors also address an aspect often glossed over in theory-heavy texts: what these algorithms actually cost on small embedded devices. Memory usage, execution time, and code size are measured and compared, giving readers a realistic view of trade-offs.

Public-key crypto and secure communication

Later chapters move into asymmetric cryptography and system-level building blocks used in secure embedded systems. Topics include public/private keys, digital signatures, RSA, SHA-256, and key derivation methods — supported by microcontroller-focused examples.

A standout section walks through a complete secure communication program that combines RSA and AES-256, demonstrating a practical hybrid approach: public-key cryptography for key exchange, and fast symmetric encryption for data transfer.

A practical starting point for secure embedded design

Practical Microcontroller Cryptography is not a book aimed at readers who simply want to recognize algorithm names. It is designed for working engineers who want to understand how cryptography behaves on real hardware — and how to integrate it into firmware responsibly.

For anyone who has wondered how secure messaging, protected storage, or encrypted device links are actually implemented on small microcontrollers, Practical Microcontroller Cryptography offers a clear and experiment-driven path from concept to working code.