PGP Email Encryption

Cryptography · Axiom Academy

REAL WORLD PGP Email Encryption How public key cryptography protects your most sensitive communications Imagine you need to send a sensitive email to a journalist, your lawyer, or a business partner. Regular email is like sending a postcard—anyone handling it along the way can read it. In 1991, a programmer named Phil Zimmermann created Pretty Good Privacy (PGP) to solve this exact problem. His timing was perfect—and controversial. Phil Zimmermann released PGP in 1991 as a free tool for human rights activists. The U.S. government wasn't happy—at the time, strong encryption was classified as a "munition" and exporting it was illegal. PGP uses a clever hybrid approach that combines the best of both symmetric and asymmetric encryption: Why use both symmetric and asymmetric encryption? Let's watch how Alice sends an encrypted email to Bob: This ciphertext is unreadable to anyone except Bob! Only Bob's private key could decrypt this! PGP introduced a revolutionary concept: instead of relying on certificate authorities (like HTTPS does), PGP uses a "web of trust" . Central authority verifies identities Transitive trust relationships Solid lines = direct verification | Dashed lines = transitive trust Key Distribution & Key Servers Once you create a PGP key pair, you need a way to share your public key with the world. This is where key servers come in. Upload your public key to a server (e.g., keys.openpgp.org) Anyone can search for and download your public key

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