How to Use OpenPGP to Encrypt Your Email Messages and Files in the Cloud

This is a guest post by Henry Chow.

Putting up your sensitive data on cloud storage could possibly give you heebie-jeebies. A good dose of cryptography, however, is sufficient to provide you the much needed peace of mind. Implementation of open-source Pretty Good Privacy (OpenPGP) is considered as the gold standard of online encryption, and when used properly, it has the capability to even thwart the likes of NSA. Read along to find out more!

Popular encryption solutions like DiskCryptor and BitLocker do not have the potential to secure files or emails in the cloud. But the industrial strength of OpenPGP encryption can not only secure the delivery of files, but also provide verification about who create and send a message using the digital signing process.

Using OpenPGP requires equal participation by both the sender and recipient. It can also be used to secure sensitive files when they are stored in vulnerable locations such as mobile devices or in the cloud. Follow the steps mentioned below to learn how to use OpenPGP to encrypt your email messages and files in the Cloud:

1. Installing gpg4win

Here, we’ll make use of gpg4win, a Windows program, which is compatible with OpenPGP. For that, simply download and run the setup program. Install GPA along with other components that are selected by default. Remember to install gog4win on all computers you on which you are required to encrypt and decrypt the files.

2.Creating the OpenPGP keys

Open GPA and click on keys, followed by new keys. Now, enter your name and click on the forward tab. Enter your e-mail address and again click forward. In case, you wish to provide a backup for your key, click on Create backup copy. Also, consider backing up the key pair into a separate drive and be wary of storing it someplace safe. As soon as the certificate is created, you can select a location to back-up the key pair. Finally, you’ll be required to enter a passphrase for the private key. Make sure you use a strong, mixed-character and long passphrase.

3. Distributing or Exporting Your Public Keys

The moment you generate a public key, it can be exported and distributed for receiving encrypted messages from other users. You are just required to right-click on the key in GPA and select Export keys and save the changes made. You can even include the public-key in your e-mail signature and publicize it on your blog or website.

4. Importing PGP keys

It should be noted that the private key is very sensitive and it should only be imported to devices and computers that will be used to decrypt the files. In order to import the public key in text format, you first need to copy the entire block of the raw key and paste it on GPA application.

5. Importing keys to GNU Privacy Assistant (GPA) on Windows

Open GPA and click on the Import tab. Now, browse and select the desired key and click open. In case you wish to import the keys to APG in Android, you are required to first copy the entire block of raw key text onto the specific device. While importing, make sure you connect your device to the computer via USB cable. Never email yourself the private key. Open the APG app and open the menu by tapping on the key icon. Tap on Import keys option. You can search the public servers in case you’re looking for public keys. Otherwise, simply select menu on the top for importing the key from QR Code, NFC, file or clipboard. The moment the key is loaded, click on the Import selected keys option.

6. Encrypting and decrypting files in Windows

Installing gpg4win installs an extension in Windows Explorer shell, which allows you to encrypt more than one file on your system with a right-click. These files would be added to TAR archive file and compressed before being encrypted.

7. Encrypting with gpg4win

To get started, right-click on the desired file and select Sign and Encrypt. Next, tick mark on Remove unencrypted original file when done, in case you wish to remove the original file. Hit on Next button to continue. Select the recipients’ public key and hit on the Add button to put them on the list. Click on Next button. If you want to add yourself to the list so, decrypt the file if needed. In case, you select to sign the file, you then need to select the private key you would like to sign the file with. Click, Next and you would be required to enter the private key’s passphrase.

8. Decrypting with gpg4win

For decrypting the file with gpg4win, right click on the encrypted file and select Decrypt and Verify. The first two options automatically default to right configuration. You can also choose to save the decrypted file in another location. Click the Decrypt and Verify option and enter your private key’s passphrase.

About the Author: Henry Chow is a managing director of an IT company – Motionwave Technologies. The company Motionwave Technologies was started in 2010. They offer IT network support to small and medium size business.