https://randhana.com/blog Thoughtful work. Real impact. en-us pulathisi.kariyawasam@gmail.com (Pulathisi Kariyawasam) pulathisi.kariyawasam@gmail.com (Pulathisi Kariyawasam) Wed, 20 May 2026 00:00:00 GMT https://randhana.com/blog/complete-guide-to-secure-connections-tls-ssl https://randhana.com/blog/complete-guide-to-secure-connections-tls-ssl A comprehensive deep-dive into TLS/SSL security - from TCP handshakes to certificate verification, covering everything you need to know about secure network connections, encryption, and how HTTPS really works. Wed, 20 May 2026 00:00:00 GMT pulathisi.kariyawasam@gmail.com (Pulathisi Kariyawasam) tlsencryptioncertificateshttpscryptography https://randhana.com/blog/understanding-diffie-hellman-key-exchange https://randhana.com/blog/understanding-diffie-hellman-key-exchange A step-by-step mathematical deep-dive into how Diffie-Hellman key exchange works - from simple paint mixing analogies to the discrete logarithm problem that makes it unbreakable. Fri, 08 May 2026 00:00:00 GMT pulathisi.kariyawasam@gmail.com (Pulathisi Kariyawasam) cryptographydiffie-hellmanmathematicskey-exchangesecurityencryptionmodular-arithmetic https://randhana.com/blog/when-a-cas-private-key-was-just-the-number-4-emudhra-incident https://randhana.com/blog/when-a-cas-private-key-was-just-the-number-4-emudhra-incident eMudhra's certificate keys got compromised in October 2026 - and one of them was literally the number 4. I take what I learned writing about TLS and Diffie-Hellman and use it to reproduce the weak key myself, step by step. Sun, 01 Nov 2026 00:00:00 GMT pulathisi.kariyawasam@gmail.com (Pulathisi Kariyawasam) securitytlscertificatescryptographyecdsapkihands-on