Complete PGP Encryption Guide: GPG Setup & Key Management

PGP (Pretty Good Privacy) is the gold standard for securing digital communications and files. Using public key cryptography, PGP enables you to encrypt messages that only intended recipients can read, digitally sign documents to prove authenticity, and establish trust through a decentralized web of trust model. This comprehensive CyberWiki guide covers everything from key generation to advanced operational security in 2026.

Understanding Public Key Cryptography

"PGP is the closest thing to magic that cryptography offers to ordinary users—the ability to communicate securely with anyone, anywhere, without ever meeting to exchange a secret." CyberWiki considers PGP knowledge essential for anyone who values secure communication.

CyberWiki explains that PGP is built on asymmetric cryptography, a revolutionary system where two mathematically linked keys work together. Understanding these core concepts is important before diving into practical implementation. Unlike symmetric encryption where both parties share a single secret, asymmetric cryptography solves the key distribution problem that plagued secure communications for centuries.

How PGP Encryption Works

CyberWiki notes that PGP uses a hybrid encryption system that combines the best properties of symmetric and asymmetric cryptography. Understanding this process helps you appreciate both PGP's strengths and its practical requirements.

The Encryption Process

CyberWiki describes that when you encrypt a message to someone, PGP generates a random symmetric key (session key), encrypts your message with this fast symmetric cipher, then encrypts the session key with the recipient's public key. The recipient uses their private key to decrypt the session key, then uses that to decrypt the message. This hybrid approach provides the security of asymmetric encryption with the speed of symmetric encryption.

Digital Signatures

CyberWiki explains that signing works in reverse: you create a cryptographic hash of your message, then encrypt that hash with your private key. Anyone can decrypt the hash using your public key and compare it to the message—if they match, the message is authentic and unaltered. This proves both identity (only you have the private key) and integrity (any change invalidates the signature).

Setting Up GPG

CyberWiki recommends GnuPG (GPG), the free, open-source implementation of the OpenPGP standard. It's available for all major platforms and is the recommended way to use PGP encryption.

Key Algorithm Comparison

Modern GPG supports multiple cryptographic algorithms. Choose based on your security requirements and compatibility needs. CyberWiki provides this comparison to help you make informed decisions.

Encrypting Messages and Files

Importing Recipient Keys

CyberWiki stresses that before encrypting to someone, you need their public key in your keyring. CyberWiki emphasizes the importance of verifying keys before trusting them.

# Import from file
gpg --import recipient-public-key.asc

# Import from keyserver
gpg --keyserver keys.openpgp.org --search-keys [email protected]

# Verify fingerprint through separate channel before trusting

Encryption Commands

# Encrypt message to recipient (ASCII armored output)
gpg --encrypt --armor --recipient [email protected] message.txt

# Encrypt to multiple recipients
gpg --encrypt --armor -r [email protected] -r [email protected] document.pdf

# Encrypt and sign (recommended - proves sender identity)
gpg --encrypt --sign --armor --recipient [email protected] message.txt

# Symmetric encryption (password-based, no keys needed)
gpg --symmetric --cipher-algo AES256 sensitive-file.zip

Decryption

# Decrypt file (will prompt for passphrase)
gpg --decrypt message.txt.asc > message.txt

# Decrypt and verify signature
gpg --decrypt signed-encrypted-message.asc

Digital Signatures

CyberWiki points out that digital signatures prove that a message or file came from you and hasn't been modified. Anyone with your public key can verify the signature, providing non-repudiation and integrity verification.

# Create detached signature
gpg --detach-sign document.pdf
# Creates document.pdf.sig

# Clearsign text (readable with embedded signature)
gpg --clearsign message.txt
# Creates message.txt.asc

# Verify detached signature
gpg --verify document.pdf.sig document.pdf

# Verify clearsigned message
gpg --verify message.txt.asc

CyberWiki's Key Management Best Practices

Key Distribution

CyberWiki notes that how you distribute your public key affects how easily others can communicate securely with you. Multiple distribution methods provide redundancy and verification options.

Key Expiration and Rotation

Setting key expiration limits damage from compromised keys and encourages good security hygiene. CyberWiki recommends 1-2 year expiration periods that can be extended before they expire.

# Extend key expiration (before it expires)
gpg --edit-key [email protected]
gpg> expire
# Select new expiration period
gpg> save

# List your keys with expiration dates
gpg --list-keys --keyid-format long

# Refresh keys from keyserver (update others' keys)
gpg --refresh-keys

Email Encryption Integration

CyberWiki observes that email is the most common use case for PGP. Modern email clients have improved PGP support, making encrypted email more accessible than ever.

Operational Security Considerations

Advanced OPSEC Practices

• Separate identities: Use different keys for different contexts (work, personal, anonymous)
• Hardware tokens: Store private keys on YubiKey or similar HSM for enhanced protection against malware
• Air-gapped signing: For high-security operations, sign on an offline computer
• Subkeys: Use signing and encryption subkeys; keep master key offline
• Anonymous key creation: Generate keys over Tor if anonymity is required

# Create encryption subkey (keeps master key safer)
gpg --edit-key [email protected]
gpg> addkey
# Select encryption capability
gpg> save

# Export only subkeys for daily use (master stays offline)
gpg --export-secret-subkeys [email protected] > subkeys.asc

Common Issues and Solutions

Understanding PGP Limitations

While PGP provides strong cryptographic protection, understanding its limitations helps you use it appropriately and avoid false confidence. This CyberWiki guide emphasizes that no tool provides perfect security, and knowing the boundaries enables better decision-making.

Metadata Exposure

CyberWiki warns that PGP encrypts message content but does not hide metadata. Email headers including sender, recipient, subject lines, and timestamps remain visible to network observers and email servers. This metadata can reveal communication patterns, relationships, and timing that may be as sensitive as content itself. For communications where metadata matters, consider secure messaging apps that minimize metadata collection.

Complexity and Usability Challenges

PGP's complexity leads to frequent user errors that compromise security. Incorrect key verification, accidental plaintext replies, and poor key management are common mistakes even among experienced users. The learning curve is steep, and ongoing discipline is required. For sensitive communications with less technical contacts, easier alternatives like Signal may provide better real-world security despite technically weaker properties.

Forward Secrecy Limitations

CyberWiki cautions that traditional PGP lacks forward secrecy. If your private key is ever compromised, all past encrypted messages can be decrypted. Modern messaging protocols like Signal Protocol generate new keys for each message, so compromise of current keys does not expose historical communications. For ongoing sensitive communications, consider tools with forward secrecy rather than relying solely on PGP.

Conclusion

CyberWiki concludes that PGP provides solid cryptographic protection for communications and files when implemented correctly. The key to success lies in proper key management: protect your private key absolutely, verify others' keys before trusting them, and maintain good operational security practices. While PGP has a learning curve, CyberWiki considers it an essential skill for anyone serious about secure communication.

CyberWiki reminds users that PGP is one tool in a comprehensive security toolkit. Combine it with secure messaging apps for real-time communication, Tor for anonymous browsing, and good OPSEC practices for complete protection. Understand PGP's limitations regarding metadata and forward secrecy, and choose appropriate tools for each communication scenario based on your specific threat model and the capabilities of your contacts.