TLS
3 articles with this tag
What is public-key cryptography — encrypting and signing with a key pair
Public-key crypto uses a 'public key' (safe to hand out) and a 'private key' (held only by the owner). Anything encrypted with the public key can only be decrypted by the matching private key, and a signature made with the private key can be verified with the public key. That asymmetry underpins TLS (HTTPS) key exchange, digital signatures, and passkeys. Defenses: don't roll your own crypto (use standard protocols and battle-tested libraries), protect and be able to revoke the private key, and keep key length and algorithms current.
What is OpenSSL — the library under HTTPS, and how to defend it
OpenSSL = the open-source library that powers HTTPS (TLS/SSL) and crypto. Most people never write it directly — they inherit it via the web server, OS, or language runtime. That's why one bug has an enormous blast radius (Heartbleed is the classic case). Defense: know which OpenSSL your stack uses, don't run EOL versions, include foundational libraries in CVE monitoring, and patch promptly. Even the certificates this site serves run crypto through an OpenSSL-family implementation underneath.
Heartbleed (CVE-2014-0160) — when memory leaked from the foundation of encrypted traffic
OpenSSL's memory over-read could leak private keys and sessions. The cause: the server trusted a claimed length and read adjacent memory. The lesson: act as if it all leaked — re-issue certificates, rotate all secrets — plus the weight of foundational software and memory safety.