GPG, or GNU Privacy Guard, is open-source encryption software used to secure email communications and files, and is often used as an alternative to proprietary encryption software.

What is GPG?

GPG (GNU Privacy Guard) is a free, open-source tool used for encrypting and digitally signing data. It enables secure communication by ensuring that only the intended recipient can access the content, and that the sender’s identity and the integrity of the message can be verified. GPG is based on asymmetric cryptography, which uses a pair of keys – one public and one private – to secure information.

How GPG appears in practice?

Examples of GPG usage:

• Encrypted email communication – A sender encrypts a message using the recipient’s public key; only the recipient can decrypt it with their private key.
• Digitally signing documents – Confirms the message’s authenticity and that it hasn’t been altered.
• Protecting confidential files – Sensitive business documents (e.g. contracts or customer data) are encrypted so only authorized recipients can open them.
• Verifying software integrity – GPG signatures validate that a software package or update hasn’t been tampered with.
• Bezpečné zálohování – Encrypting backup files ensures data remains secure even if storage is compromised.

These uses show GPG is not just for tech experts. It’s also suitable for businesses that need to protect sensitive data and maintain trust in communications.

GPG vs. related terms

• GPG vs. PGP – GPG is a free, open-source alternative to the commercial PGP (Pretty Good Privacy). Both are compatible.
• Encryption vs. signing – Encryption protects data confidentiality; signing verifies identity and message integrity.
• Symmetric vs. asymmetric cryptography – GPG uses asymmetric cryptography: encryption is done with a public key, decryption with a private key.

Understanding these distinctions helps organizations choose the right tools and methods for different security needs.

How to implement GPG in your company 

Steps for adoption:

1. Create a policy for encrypting communication and sensitive data.
2. Generate GPG key pairs for all key personnel and establish a key management process.
3. Integrate GPG into email clients, e.g. Thunderbird with the Enigmail plugin.
4. Train employees on how to use GPG effectively in daily communications.
5. Review and rotate keys regularly, including proper archival and revocation procedures.

Many companies still rely on unsecured email or weak encryption. GPG is a cost-effective way to boost communication security and data privacy. It's a practical addition to a broader information security strategy – accessible even for small businesses.