> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ahmadraza.in/llms.txt
> Use this file to discover all available pages before exploring further.

# GPG.Encryption

# **GPG Encryption & Decryption Guide (Mac CLI)**

## **Purpose**

This document outlines the secure procedure for encrypting and decrypting files using **GNU Privacy Guard (GPG)** public/private key pairs on macOS. It is intended for scenarios where sensitive files (e.g., source code, credentials) must be transferred securely so that **only the intended receiver** can decrypt them.

***

## **1. Installation**

Install GPG on macOS via Homebrew:

```bash theme={null}
brew install gnupg
```

***

## **2. Roles in the Process**

* **Receiver**: The individual or entity that will decrypt the file. They must generate and securely store their GPG private key.
* **Sender**: The individual encrypting the file. They use the receiver’s public key to encrypt the content.

***

## **3. Process Overview**

1. **Receiver generates GPG keypair**
2. **Receiver exports and shares public key**
3. **Sender imports receiver’s public key**
4. **Sender zips the files to be sent**
5. **Sender encrypts the zip using receiver’s public key**
6. **Sender shares the encrypted file**
7. **Receiver decrypts the file using private key**
8. **Receiver extracts the original files**

***

## **4. Step-by-Step Guide**

### **Step 1: Generate GPG Keypair** *(Receiver only)*

```bash theme={null}
gpg --full-generate-key
```

Follow the prompts to provide:

* **Name**
* **Email address**
* **Passphrase** (must be strong and kept secure)

**Export Receiver’s Public Key:**

```bash theme={null}
gpg --armor --export "receiver@email.com" > receiver-public-key.asc
```

* Share `receiver-public-key.asc` with the **sender** via a secure channel.
* **Never** share your private key.

***

### **Step 2: Import Receiver’s Public Key** *(Sender only)*

```bash theme={null}
gpg --import receiver-public-key.asc
```

Verify key exists:

```bash theme={null}
gpg --list-keys
```

***

### **Step 3: Create the ZIP File** *(Sender only)*

```bash theme={null}
zip -r secret.zip folder_to_send
```

***

### **Step 4: Encrypt the ZIP File** *(Sender only)*

Basic binary encryption:

```bash theme={null}
gpg -e -r "receiver@email.com" secret.zip
```

Creates:

```
secret.zip.gpg
```

ASCII-armored output (for easier emailing):

```bash theme={null}
gpg -e -a -r "receiver@email.com" secret.zip
```

Creates:

```
secret.zip.asc
```

***

### **Step 5: Share the Encrypted File**

Send `secret.zip.gpg` or `secret.zip.asc` to the receiver via:

* Secure file transfer (SFTP, corporate portal)
* Encrypted email
  **Do not** send over insecure channels like public chat.

***

### **Step 6: Decrypt the File** *(Receiver only)*

Binary format:

```bash theme={null}
gpg -o secret.zip -d secret.zip.gpg
```

ASCII-armored format:

```bash theme={null}
gpg -o secret.zip -d secret.zip.asc
```

Enter your **private key passphrase** when prompted.

***

### **Step 7: Extract the Files** *(Receiver only)*

```bash theme={null}
unzip secret.zip
```

***

## **5. Quick Reference Commands**

| Action            | Command                                         |
| ----------------- | ----------------------------------------------- |
| Export public key | `gpg --armor --export "email" > public-key.asc` |
| Import public key | `gpg --import public-key.asc`                   |
| Encrypt           | `gpg -e -r "email" file.zip`                    |
| Decrypt           | `gpg -o file.zip -d file.zip.gpg`               |

***

## **6. Security Best Practices**

* Always verify the public key’s **fingerprint** with the receiver before encrypting.
* Store private keys in a secure, access-controlled environment.
* Use **strong passphrases** for private keys and never share them.
* Keep an **audit log** of who received encrypted files and when.
* If possible, use **Out-of-Band verification** for key exchange.