Introduction to the PRESENT Cipher

If you’ve ever looked into cryptography for low-power devices, things like RFID tags, IoT sensors, or smart cards, then standard ciphers like AES can be overkill. They're secure, but they also demand more memory and processing power than some tiny devices can handle.

So comes PRESENT: a lightweight block cipher designed in 2007 specifically for environments where every byte and CPU cycle counts. It was proposed by researchers from Orange Labs and Ruhr-University Bochum, and is even standardized in ISO/IEC 29192-2.

From a cryptanalytic perspective, PRESENT is a great study case. It's a Substitution-Permutation Network (SPN), one of the most popular ways of constructing symmetric ciphers. In particular, its permutation layer is really simple in lieu of it needing to be fast, and is overall a cipher that's easy to imagine.

Over the next few lessons, we’ll use PRESENT to explore symmetric cryptanalysis methods like differential and linear cryptanalysis, and see what it takes to break (or at least weaken) a cipher.

Small cipher, big learning potential. Let's get started then: Hello World!!