Import a GPG Private Key and Encrypt/Decrypt Messages Using GPG

GPG Private Key Import and Message Decryption Guide

Overview: This guide provides step-by-step instructions for importing GPG keys, decrypting encrypted messages, and encrypting messages. GPG stands for GNU Privacy Guard which is  used to protect information using encryption.

1. Install GPG

Step 1(A): Update the package repository and install GPG

Step 1(B): Verify that GPG is installed correctly by checking the version:

2. Generate new private GPG key

Step 2(A): A private GPG key is a secure file used to decrypt encrypted messages. Generate a key if you don’t already have a private key. This key will be used to decrypt messages. If a private key already exists, proceed to Step 3.

Step 2(B): Follow the prompts:

Select key type: Specify the kind of key you want, or press Enter to accept the default.(RSA and RSA)

Key size: Specify the key size you want, or press Enter to accept the default.

Key expiration: Type your preferred duration (e.g., 1y for 1 year) or 0 for no expiration

Verify that your selections are correct.

User ID information: Enter your name and a verified email address

Comment: Optional

Passphrase: Type a strong passphrase to protect the private key

Step 2(C): After generation, confirm the key:

3. Import an Existing Private GPG Key

Step 3(A): If an existing private key file is already available (for example: support_private_key.asc), upload it to the server and import it using the following command:

The private key file name may vary. Replace support_private_key.asc with the actual file name provided.

Step 3(B): When prompted, enter the private key passphrase to complete the import process

Step 3(C): List the secret keys to confirm that the private key was imported successfully:

4. Decrypt an Encrypted Message File

Step 4(A): If an encrypted file is received (for example, message.asc), use the following command to decrypt it:

Step 4(B): When prompted, enter the private key passphrase to proceed with decryption.

Step 4(C): After successful decryption, the decrypted content will be displayed directly in the terminal.

Step 4(D): Run below command to save the decrypted content into a file.

5. Decrypt an Encrypted Message from Email (Text)

Step 5(A): Copy the entire encrypted block from `-----BEGIN PGP MESSAGE-----` to `-----END PGP MESSAGE-----`)

Step 5(B): Create a file and paste the encrypted message into it:

Step 5(C): Save and close the file.

Step 5(D): Decrypt the message using the following command:

6. Import a Public GPG Key

Step 6(A): A public GPG key is used to encrypt messages so that only the intended recipient can decrypt them using their private key. After receiving the public key file (for example: public_key.asc), upload it to the server and import it using the following command:

7. Encrypt and Send a Message

Step 7(A): To encrypt a message for a recipient using their public key, run:

Step 7(B): Send the contents of message.asc via email (Outlook, Gmail, etc.).