This work started with OpenSSL and became a broader secure-architecture exercise. I generated keys, signed certificates, built a CA chain, tested encryption and signature operations, and used the lab to reason about TLS, VPN/IPSec, segmentation, and trust boundaries.
The useful lesson was that PKI is both a cryptographic system and an operational system. A certificate chain can be mathematically valid and still be the wrong design if issuance, storage, renewal, or revocation are ignored.
I connect this project with my RSA/CA implementation. The RSA project helped me understand the primitives. The OpenSSL lab helped me understand how those primitives appear in real tooling and infrastructure decisions.
For internship roles, this is relevant to security architecture, cloud security, network security, code signing, and any position where trust relationships have to be explained clearly.