If you use AES in the real world (like securing a web browser or a VPN), you almost always use AES-GCM. This provides Authenticated Encryption with Associated Data (AEAD). It encrypts the message so no one can read it, and attaches a cryptographic tag to prove no one altered it in transit.
Ascon v1.2 does this natively. When you encrypt a payload with Ascon, it simultaneously encrypts the data and generates that same kind of authentication tag.
- AES is a Block Cipher: It takes your data, chops it into rigid 128-bit blocks, and scrambles each block through a massive, complex mathematical maze (a substitution-permutation network).
- Ascon is a Sponge Function: Instead of rigid blocks, Ascon uses the same "sponge" concept we talked about with SHA-3. It maintains a 320-bit internal state. It continuously "absorbs" your plaintext into that state, scrambles it lightly, and "squeezes" out the ciphertext.
This is the real reason Ascon exists.
- AES is for powerful machines: AES is computationally expensive. However, modern laptops, servers, and smartphones have dedicated silicon on their CPUs (called AES-NI) just to process AES instantly. On big machines, AES is the undisputed king.
- Ascon is for The Edge (IoT) Devices: If you try to run AES on a tiny, battery-powered 8-bit microcontroller (like an Arduino inside a smart thermostat, a pacemaker, or a car tire pressure sensor), it drains the battery rapidly and consumes too much RAM.
Because Ascon uses a lightweight sponge and a very simple 5-bit substitution box, it can be implemented in hardware using incredibly few logic gates. On microcontrollers, Ascon runs 3 to 4 times faster than AES-GCM and uses about 30% less RAM, all while providing the exact same 128-bit security level.