GPG Decrypt vs CypherAir

This app is designed to allow you to read on your iPhone, files that have been encrypted on your Mac using GPG. The workflow is: 1. Encrypt a file on your Mac using GPG (AEAD - Authenticated Encryption with Associated Data, is not supported at the moment, see support page). 2. Transfer the encrypted file and your private key to your iPhone (using iCloud Drive, Dropbox, Google Drive, or any other cloud storage service) 3. Use this app to decrypt and view the file content on your iPhone This is particularly useful for securely accessing sensitive documents on your iPhone without storing the decrypted content permanently on the device. Features - Decrypt GPG-encrypted files - Support for private key authentication - Secure file handling with security-scoped resources - Display-only decryption (no persistent storage of decrypted content) Usage 1. Select the encrypted file you want to decrypt 2. Select your private key file 3. Enter the passphrase for your private key 4. Tap "Decrypt" to decrypt the file 5. The decrypted content will be displayed on screen. It is not saved to your device. GPG ([GNU Privacy Guard](https://gnupg.org/)) is a widely used open-source implementation of the OpenPGP standard. This app only supports asymmetric encryption (public/private key). It cannot decrypt files that were encrypted using symmetric encryption (password-only encryption). Using GPG on Mac OS - Install GnuPG: brew install gnupg - Generate a new GPG key: gpg --full-generate-key - Choose option 1 (RSA and RSA) - Choose 4096 bits - Choose 0 (key does not expire) - Enter your name and email - Enter a secure passphrase - Export your private key (required for decryption on iPhone): gpg --export-secret-keys --armor your-email@example.com > private_key.asc - Replace `your-email@example.com` with the email you used when creating the key - Enter your passphrase when prompted - The private key will be saved to `private_key.asc` - Transfer this file to your iPhone for use with the app - Encrypting a file: gpg --encrypt --recipient your-email@example.com your_file.txt - This creates `your_file.txt.gpg` - Transfer this encrypted file to your iPhone for decryption with the app Decrypting a file on Mac: gpg --decrypt your_file.txt.gpg > decrypted_file.txt - This will prompt for your private key passphrase - The decrypted content will be saved to `decrypted_file.txt` Transferring files to iPhone You can transfer the encrypted file and private key to your iPhone using various cloud storage services: - iCloud Drive - Dropbox - Google Drive - OneDrive - Or any other cloud storage service that provides iOS file access Security - All file operations use security-scoped resources - Passphrase is never stored - Files are copied to the app's documents directory for processing - Decrypted content is only displayed and not saved to the device - No persistent storage of sensitive information

CypherAir is a fully offline, open-source OpenPGP encryption tool built for iOS, iPadOS, macOS and VisionOS. It makes zero network connections. There is no telemetry, no tracking, and no possibility of data leakage. Two Encryption Profiles • Universal (Profile A) — Interoperable with GnuPG and all major PGP implementations. RFC 4880 compliant, employing Ed25519 and X25519 with SEIPDv1. • Advanced (Profile B) — Implements the latest OpenPGP standard, RFC 9580, with Ed448 and X448, authenticated encryption via AEAD (SEIPDv2), and Argon2id passphrase protection. Capabilities • Encrypt and decrypt text and files, processed as streams for efficiency • Create digital signatures — cleartext for messages, detached for files • Exchange public keys through QR codes using the system Camera, with no camera permission required • Manage multiple keys, each with its own encryption profile • Safeguard private keys in the Secure Enclave, unlocked only by Face ID or Touch ID Privacy Through Architecture • The sole system permission is the Face ID usage description • Private keys never leave the protection of Secure Enclave wrapping Open Source CypherAir is open source and available under the GNU General Public License v3.0 or later (GPL-3.0-or-later) or the Mozilla Public License 2.0 (MPL-2.0). Additional languages are in progress. Disclaimer No Warranty: You expressly acknowledge and agree that use of the Licensed Application is at your sole risk. To the maximum extent permitted by applicable law, the Licensed Application and any services performed or provided by the Licensed Application are provided "as is" and "as available," with all faults and without warranty of any kind, and Licensor hereby disclaims all warranties and conditions with respect to the Licensed Application and any services, either express, implied, or statutory, including, but not limited to, the implied warranties and/or conditions of merchantability, of satisfactory quality, of fitness for a particular purpose, of accuracy, of quiet enjoyment, and of noninfringement of third-party rights. No oral or written information or advice given by Licensor or its authorized representative shall create a warranty. Should the Licensed Application or services prove defective, you assume the entire cost of all necessary servicing, repair, or correction. Some jurisdictions do not allow the exclusion of implied warranties or limitations on applicable statutory rights of a consumer, so the above exclusion and limitations may not apply to you.