#security

4 articles

Firewalls: Filtering the Traffic

A firewall decides which traffic may pass by matching packets against rules on address, port, and protocol. The real leap is memory: a stateful firewall welcomes the replies to connections you started while turning away strangers who arrive uninvited.

9 min read·Jul 21, 2026

Computer Science

Public-Key Cryptography

One-way functions let two people who have never met build a shared key in the open — and the same asymmetry that protects the key is what a quantum computer would dismantle.

10 min read·Jul 18, 2026

Networks & the Internet

Certificates and the Chain of Trust

TLS hands your browser a public key and says 'encrypt to me' — but anyone can generate a key. Certificates and a chain of signatures reaching back to a short list of preinstalled authorities are what tie that key to a real identity.

10 min read·Jul 16, 2026

Networks & the Internet

TLS: Encrypting the Web

Plaintext HTTP let anyone on the path read your passwords. TLS wraps the connection in encryption by using slow asymmetric crypto only to authenticate the server and agree a key, then switching to fast symmetric crypto for the data.

10 min read·Jul 14, 2026