PGP Encryption

PGP encryption allows you to secure your communications by encrypting files, messages, and emails. This guide covers the fundamental encryption and decryption operations using both command-line and GUI tools.

Basic Encryption Concepts

PGP uses a hybrid encryption system that combines:

1. Public-key (asymmetric) encryption: Uses recipient's public key to encrypt data
2. Symmetric encryption: Uses a randomly generated session key for the actual file encryption
3. Digital signatures: Ensures authenticity and integrity of the message

Encrypting Files

Command Line (GPG)

To encrypt a file for a specific recipient:

# Encrypt a file for a specific recipient
gpg --encrypt --recipient recipient@email.com document.txt

# This creates an encrypted file: document.txt.gpg

To encrypt and sign a file (recommended):

# Encrypt and sign a file
gpg --encrypt --sign --recipient recipient@email.com document.txt

Using GUI Applications

Kleopatra/GPG4Win:

1. Right-click the file in Explorer
2. Select "Sign and Encrypt"
3. Choose recipient(s)
4. Complete the encryption process

GPG Suite (macOS):

1. Right-click the file in Finder
2. Select "Services" → "OpenPGP: Encrypt File"
3. Choose recipient(s)

Decrypting Files

Command Line Decryption

# Decrypt a file
gpg --decrypt encrypted-file.gpg > decrypted-file.txt

# If the file is signed, GPG will verify the signature automatically

GUI Decryption Applications

Kleopatra/GPG4Win:

1. Double-click the .gpg file
2. Enter your passphrase when prompted

GPG Suite (macOS):

1. Double-click the encrypted file
2. Enter your passphrase when prompted

Text Encryption

To encrypt text messages (e.g., for secure messaging):

# Create a text file with your message
echo "Secret message" > message.txt

# Encrypt the message
gpg --encrypt --armor --recipient recipient@email.com message.txt

# The output file (message.txt.asc) contains ASCII-armored encrypted text
# that can be copied and pasted into emails or messaging apps

Verifying Signatures

To verify a signed file:

# Verify a signature
gpg --verify document.txt.sig document.txt

Best Practices

1. Always verify signatures when decrypting files from others
2. Use trusted channels for initially exchanging public keys
3. Sign your encrypted messages to provide authentication
4. Keep your private key secure and protected by a strong passphrase
5. Use ASCII armor (--armor flag) when sharing encrypted text via text channels

Next Steps

• Email Integration - Configure email clients for PGP
• Best Practices - Advanced security considerations

Overview

Content will be added soon.

Key Points

• Important information about PGP Encryption
• Step-by-step instructions
• Best practices