Welcome to the official documentation for GPG Symmetric Encrypt. This application provides a streamlined, secure way to encrypt and decrypt files on your Android device using the industry-standard OpenPGP protocol.

What is Symmetric Encryption?

Most people are familiar with Asymmetric encryption (using Public and Private keys). However, this app focuses on Symmetric Encryption

• How it works: You use a single „Shared Secret“ (a password or passphrase) to both lock (encrypt) and unlock (decrypt) your data.
• The Benefit: You do not need to manage complex keyrings, exchange public keys with recipients, or worry about private key loss. As long as both the sender and receiver know the passphrase, the data can be exchanged securely.
• Security: We use strong encryption algorithms provided by the Bouncy Castle cryptography library, ensuring your data remains private even if the file is intercepted.

GPG Compatibility

Compatibility is a core pillar of this application. Files encrypted with this app are 100% compliant with the OpenPGP standard (RFC 4880).

• Cross-Platform: You can encrypt a file on your Android phone and decrypt it on a PC using standard tools like gpg (GNU Privacy Guard), Kleopatra, or GPG4Win.
• Command Line Usage: A file encrypted in this app can be decrypted via the terminal using: gpg --decrypt filename.pgp
• Interoperability: Any software that supports „Password-protected“ or „Symmetric“ PGP encryption will be able to process files generated by this app.

Data Sources (Input)

The app is designed to handle various types of data. You can bring data into the app from the following sources:

• Internal Storage: Select any file (documents, images, videos) from your device’s internal memory via the system file picker.
• External Storage/SD Cards: Access files stored on removable media.
• Direct Text Input: Encrypt raw text or notes directly within the app interface to create secure text files.
• Shared Content: Receive files sent from other apps using the Android „Share“ menu.

Data Sinks (Output)

Once your data is processed, you have full control over where the encrypted or decrypted output goes:

• Local File System: Save the resulting .pgp (encrypted) or original format (decrypted) files back to your device or SD card.
• Clipboard: For text-based encryption, you can copy the resulting PGP block directly to your clipboard for pasting into other applications.
• Android Share Sheet: Immediately send the encrypted file to other apps, such as:

Version: 1.0 (Build 2) Target SDK: Android 36