PGP Encryption Guide
Published: July 12, 2026 | Reading Time: 12 min
1. What is PGP?
Pretty Good Privacy (PGP) is an encryption program that provides cryptographic privacy and authentication for data communication. Originally created by Phil Zimmermann in 1991, PGP has become the de facto standard for email encryption and digital signatures. The OpenPGP standard (RFC 4880) defines the protocol, and GnuPG (GPG) is the most widely used free implementation.
PGP uses a hybrid cryptosystem combining symmetric-key cryptography for speed and public-key cryptography for secure key exchange. Each user generates a key pair: a public key shared freely and a private key kept secret.
2. Key Generation
Generating a PGP key pair is the first step. Use GnuPG on a trusted, offline computer for maximum security. The command gpg --full-generate-key launches the interactive key generation wizard. Select RSA (4096 bits) for both signing and encryption. Set an expiration date — one to two years is standard practice.
Your private key must be protected with a strong passphrase. Store it on an encrypted volume. Your public key should be uploaded to key servers for discovery by correspondents.
3. Key Management
Key management is the most critical aspect of PGP security. Your private key should never leave machines you control. Create a revocation certificate immediately after key generation and store it in a secure offline location. Regularly rotate subkeys while keeping your primary key offline.
The Web of Trust model requires verifying key fingerprints through out-of-band channels before trusting a key. Never rely solely on key server downloads without independent verification.
4. Encrypting & Signing
Encryption ensures only the intended recipient can read your message. Signing proves the message originated from you and has not been modified. Always sign your encrypted messages — this provides both authentication and non-repudiation. Use gpg --encrypt --sign for combined operation.
For email integration, Thunderbird with Enigmail or K-9 Mail on Android provide seamless PGP support. For manual file encryption, gpg --encrypt --recipient recipient@example.com document.pdf encrypts a file for a specific recipient.
5. Best Practices
Use a dedicated key for each identity context. Rotate keys periodically. Keep your private key on an encrypted volume with strong passphrase protection. Verify fingerprints through independent channels. Consider using hardware security modules like YubiKey for private key storage. Regularly check for key revocations on keyservers.