S/MIME, PGP, and GPG: Securing Digital Communication for True Privacy

In this podcast discussion explores email encryption technologies, primarily PGP (Pretty Good Privacy), GPG (GNU Privacy Guard), and S/MIME (Secure/Multipurpose Internet Mail Extension). Discussion details how these systems use public and private key cryptography for confidentiality, authentication, and integrity in digital communication. While all aim to secure emails, it highlights their fundamental differences, particularly in their trust models – PGP/GPG utilise a "web of trust", whereas S/MIME relies on a hierarchical Public Key Infrastructure (PKI) with Certificate Authorities (CAs). It also discuss practical and theoretical vulnerabilities, such as pass-phrase compromises, public key tampering, operating system weaknesses, Trojan horse attacks, and electronic surveillance, alongside the more recent EFAIL attacks which exposed flaws in email client implementations. Overall, the podcast collectively present a comprehensive overview of these email security methods, their operational mechanisms, benefits, and challenges, including their impact on usability and broader enterprise security requirements.