PKI for a Startup: Certificates, CAs and TLS Grading

<p>Nimbus Health, a fictional Bengaluru health-tech start-up, runs internal services over plain HTTP and is about to face a hospital partner's security review of its public endpoints.</p><p>In four lessons you learn public-key cryptography and digital signatures in practice, how X.509 certificates and chains of trust work, why a root CA stays offline and an issuing CA is constrained, how to make certificate signing requests (CSRs) with subject alternative names, and how to grade a TLS configuration (protocol versions, cipher suites, chain, HSTS).</p><p>You build the PKI in Bartman's in-browser Crypto Workbench, a practice certificate authority that issues real X.509 certificates; the server parses and verifies them. If you prefer real OpenSSL, paste your PEM files in instead. Part of the Bartman Cybersecurity track (Professional Certificate in Cybersecurity, LSBF).</p>

Tools: PKI, X.509, TLS, Certificate authorities, CSR, OpenSSL concepts