PKI in plain language
Mango CA Team, PKI & Certificates·3 min read
Establishing link000
The short answer
Public key infrastructure (PKI) is the set of roles, policies and software that issue, manage and revoke digital certificates. It lets anyone verify that a key belongs to a specific person, organization or server, which is what makes digital signatures legally meaningful and encrypted connections trustworthy. A licensed Certifying Authority sits at the top of that chain of trust.
Every participant in PKI has a pair of keys. The private key stays secret and is used to sign or decrypt. The public key is shared freely and is used to verify a signature or encrypt a message to the owner. The two are mathematically linked: what one does, only the other can undo.
That solves half the problem. Anyone can generate a key pair, so a public key on its own proves nothing about who owns it. The other half is the certificate.
A certificate is a signed statement from a Certificate Authority that says: this public key belongs to this person, organization or server, and we checked. Because the CA signs the statement with its own key, and the CA's key is trusted by operating systems, browsers and, in Bangladesh, by law, the chain of trust reaches from your signature back to a root everyone recognises.
| Role | Job |
|---|---|
| Certificate Authority (CA) | Issues and signs certificates; publishes which ones have been revoked |
| Registration Authority (RA) | Verifies identity before the CA issues a certificate |
| Subscriber | The person, organization or server that holds the certificate and private key |
| Relying party | Anyone who checks a signature or connection against the certificate |
| Controller of Certifying Authorities (CCA) | The government office that licenses and audits CAs in Bangladesh |
Mango CA has held a CA licence from the Office of the CCA since 2011, operating under the ICT Act 2006 and the IT (Certifying Authorities) Rules 2010.
NEXT STEP
Digital signature and SSL certificates from a CCA-licensed authority, with local documentation and support.