If mobile security is a priority for you, file encryption should be on your radar. Unlike simply storing files in an encrypted folder, this approach allows you to encrypt files that can be accessed on your device or shared securely with others. The recipient will be the only one able to view the content, thanks to the magic of encryption.
At the heart of this process is the OpenKeyChain app, which simplifies file encryption for Android users. Before you dive into the app, it’s essential to understand a few key concepts.
It’s all about keys
For those familiar with public key encryption on desktop systems, the concept will feel familiar. Public key encryption relies on a pair of keys: a private key, which remains on the recipient’s device, and a public key, which is shared with anyone needing to send an encrypted file. Files encrypted with a private key can only be decrypted by someone who possesses the corresponding public key. Without that public key, the file remains inaccessible.
This method is not only effective but also straightforward to implement on Android devices. Let’s explore how to get started.
What you’ll need
To begin, ensure you have an Android device and the OpenKeyChain app installed. Once you have the app, you’re ready to proceed.
Manage the keys
First, you need to create your own key. Navigate to the Keys tab within the app, tap the three-dot menu in the upper-right corner, and select “Manage my keys.” If you’re collaborating with someone who doesn’t have OpenKeyChain, they will need to send you their public key, which you can import from the My Keys section by selecting the “+” icon and then “Import from File.” Locate the file they sent, and you’ll be set to go.
Encrypting a file
With your key created, you can now encrypt files. You have the option to encrypt a file for another user (using their public key) or to save a file on your device or Google Drive using your own public key. Remember, files saved on your device will have a .gpg extension. If someone gains access to your device, they could potentially view these files without needing your decryption password, as it automatically aligns with the key pair.
However, there’s a silver lining: you can disguise these files to make them less conspicuous. Additionally, files stored in Google Drive remain secure, as your public key is stored locally on your device, preventing unauthorized access even if someone compromises your Google account.
To encrypt a file, follow these steps:
1. Open the Encrypt/Decrypt page
Tap the three-line menu on the main page and select Encrypt/Decrypt.
2. Encrypt the file
On the next page, tap “Encrypt files.” Here, you’ll choose whether the file is for another user or for your own storage. If it’s for someone else, select their public key. Afterward, tap “Encrypt to,” enter the recipient’s name, choose the relevant key, and then tap “Add file(s).” Locate the file you wish to encrypt, and save it to your desired location.
Once saved, you can share the encrypted file through your usual channels, whether that be email or messaging apps.
Decrypting a file
The decryption process is equally straightforward. Simply navigate to the Encrypt/Decrypt section, tap “Select input file” under Decrypt/Verify, and find the file you wish to open. You can access it directly within OpenKeyChain, and you’re all set.
