Rijndael & AESLib

Ciphering

In today’s unstable world — marked by geopolitical shifts, social fragmentation, and digital aggression — the protection of information has become an urgent necessity. For advanced tech specialists, regardless of their main discipline, understanding cryptography is now as essential as mathematics, computer science, finance, law, or even self-defense.

Modern cryptosystems fall into two main categories: asymmetric cryptography (public-key systems) and symmetric-key algorithms (private-key systems).

The key difference lies in how encryption keys are managed. Asymmetric systems, such as RSA, are used in internet transport layers — protocols like SSL and TLS — where speed and accessibility are critical. Symmetric-key algorithms, in contrast, are descendants of classic military encryption methods, designed for uncompromising data protection.

Rijndael

One of the best examples of the latter is AES — Advanced Encryption Standard, also known as Rijndael, created in 2001 by Belgian cryptographers Joan Daemen and Vincent Rijmen, and adopted as the U.S. encryption standard (FIPS PUB 197).

Impression

As an educational project, I implemented Rijndael in C++ — and it turned out to be a fascinating experience.

As an astrodynamicist, I’m used to complex math like calculation of orbital transfers, Lambert solvers, and sophisticated guidance algorithms. I expected something like this… But AES surprised me! It’s not about continuous equations; it’s about discrete manipulation. AES doesn’t “calculate” in the usual sense; it shreds information, transforming it into noise where no pattern survives.

C++ proved to be the best language for such work: it handles finite-field arithmetic naturally, letting Rijndael’s structure reveal itself in pure mathematical form. AES is powerful not only because of its math, but because of its logic: it works below the semantic level, breaking and rebuilding the very carrier of data, making straightforward cryptanalysis nearly impossible.

Even AES-128 offers protection beyond practical decryption; AES-256 is believed to resist quantum attacks — its brute-force time exceeding the expected lifespan of the Universe.

Implementation

I’ve released my implementation as an open-source C++ toolset Rijndael AESLib (C++ static library and C# encryption app).

You’re welcome to use it — for learning or to protect your own data. But remember: AES is serious, military-grade technology. If you lose your password, your encrypted data is gone FOREVER. No “King’s men,” no Pentagon, and no Lubyanka can bring it back!