Why use PKI or PGP with Digital Signature?

Digital signatures employ the PKI (Public Key Infrastructure) standard and the PGP (Pretty Good Privacy) encryption program. Both of them address security issues associated with transmitting public keys.

They authenticate using the sender’s public key belonging to that individual and verify the sender’s identity.

PKI serves as a framework for services to create, distribute, control, and verify public key certificates. PGP is a variation of the PKI standard, utilizing asymmetric and public key cryptography. However, it differs in how it associates the public key with the user’s identity.

PKI uses a Certificate Authority (CA) to authenticate and bind the user’s identity to the digital signature, while PGP relies on trusted websites. PGP users choose individuals they trust to verify identities, while PKI users rely on trusted CAs.

The security effectiveness of digital signatures depends on the strength of the private key’s security. Without PKI or PGP, it is impossible to prove someone’s identity or revoke a compromised key. Malicious actors find it easier to impersonate users.