PKI & Certificate Guides

Learn certificate structures, ASN.1, RSA key encoding, TLS, hashing, trust chains, and public key infrastructure.
PKI & Certificates

Hash Functions: MD5, SHA-256, BLAKE2 & When to Use Each

A practical guide to cryptographic hash functions — which are broken (MD5, SHA-1), which to use (SHA-256, BLAKE2), and how they're used in payment security.
8 min read
PKI & Certificates

ASN.1 & X.509 Certificates: A Practical Guide

Understand ASN.1 DER/PEM encoding, X.509 certificate structure, OIDs, and how to parse certificates and keys using online tools.
11 min read
PKI & Certificates

Base64 Encoding Explained: Standard, URL-Safe & Use Cases

Everything about Base64 — how it works, standard vs URL-safe variants, use in JWTs and certificates, and common mistakes to avoid.
7 min read
PKI & Certificates

RSA DER Public Key: Format, Structure & Decoding

How RSA public keys are encoded — DER and PEM formats, ASN.1 structure, extracting Modulus and Exponent, PKCS#1 vs PKCS#8 differences.
8 min read
PKI & Certificates

SSL/TLS Certificates: X.509 Structure, Chain & Validation

A complete guide to SSL/TLS certificates — X.509 structure, certificate chains, self-signed certificates, CSR generation, and certificate validity.
10 min read
Back to Guides