Category
7 articles in this category.
AES-CCM encrypts and authenticates data with a single AES key by combining counter mode with a CBC-MAC. Learn how its blocks are formatted, how the tag is computed and hidden, and why CCM powers Wi-Fi security, Bluetooth Low Energy, and many small devices.
18 min read
AES-SIV is an authenticated encryption mode that keeps working when a nonce is reused. Learn how its CMAC-based S2V function builds a synthetic IV, how that value becomes both the tag and the counter, and why SIV is the standard choice for key wrapping.
15 min read
OCB encrypts and authenticates in a single pass, using about one AES call per block. Learn how its secret offsets turn AES into a tweakable cipher, how the tag comes from a checksum, and what the 2018 attacks on OCB2 mean for the version in RFC 7253.
17 min read
XChaCha20-Poly1305 extends ChaCha20-Poly1305 with a 192-bit nonce, so you can simply pick a random nonce for every message. Learn how HChaCha20 builds a fresh subkey, how the rest of the AEAD works, and why the bigger nonce makes collisions a non-issue.
15 min read
In August 2025, NIST standardized a cipher small enough to run on a battery-powered sensor and simple enough to fit its whole state in five CPU registers. Learn how Ascon's sponge-based permutation delivers real authenticated encryption at a fraction of AES-GCM's footprint.
14 min read
AES-GCM does two jobs at once: it hides your data AND proves nobody tampered with it. Learn how Galois/Counter Mode combines AES with GHASH authentication to become the default choice for TLS, IPsec, and disk encryption.
10 min read
TLS 1.3's second mandatory cipher suite pairs ChaCha20 encryption with the Poly1305 message authenticator, delivering AES-GCM-equivalent security without needing any special hardware. Here's how the pairing works.
9 min read
