Cryptography
Deep-dives into the maths that secures the internet: hash functions, digital signatures, the SHA family and the SHAttered collision that gave this site its name. Explainers and reporting for people who want to understand how the primitives actually work.
Post-Quantum Cryptography: 50% of Web Now Safe [2026]
The quiet migration to post-quantum cryptography stopped being quiet in 2026. For the first time, more than half of the human web traffic flowing through Cloudflare is now…
Cryptographic Hash Functions Explained
A cryptographic hash function is one of the quiet workhorses of modern computing. It takes data of any size and turns it into a short, fixed-length fingerprint, and…
Digital Signatures Explained: How They Work and Why Hashes Matter
A digital signature does for electronic data what a handwritten signature and a tamper-evident seal do together for paper: it proves who created something and shows that nobody…
The SHAttered SHA-1 Collision, Explained
On 23 February 2017, researchers at the Cryptology Group at CWI Amsterdam and Google Research published two different PDF files that share the same SHA-1 hash. The digest…
SHA-256 Explained: How It Works and Why It Matters
SHA-256 is the hash function that quietly secures most of the systems you touch every day. It signs the certificate behind the padlock in your browser, fingerprints the…
Hashing and Cryptography Explained
Cryptography is the science of protecting information so that only the intended parties can read it, verify it, or trust where it came from. It powers nearly everything…
