Answers to common questions about iPGMail and PGP.

What is PGP?

PGP (Pretty Good Privacy) is an encryption system that lets you send private messages only the intended recipient can read. It uses two keys:

• Public key — share this freely. Others use it to encrypt messages to you.
• Private key — keep this secret. You use it to decrypt messages sent to you.

Think of it like a mailbox: anyone can drop a letter in the slot (encrypt with your public key), but only you have the key to open it (your private key).

What's the difference between PGP and OpenPGP?

OpenPGP is the open standard (RFC 4880 and RFC 9580) based on the original PGP protocol. iPGMail implements OpenPGP, which means it's compatible with:

• GPG (GNU Privacy Guard) on Mac, Windows and Linux
• Mailvelope for webmail
• Other OpenPGP-compliant apps on any platform

In everyday conversation, "PGP" and "OpenPGP" are used interchangeably.

Where can I learn more about PGP?

For background reading, these Wikipedia articles are good starting points:

• Public-key cryptography
• Pretty Good Privacy

Does iPGMail work with Gmail, Outlook, or other email providers?

Yes. iPGMail works with any email provider — Gmail, Outlook, Yahoo Mail, iCloud, Fastmail, or your own mail server.

iPGMail encrypts your message before it's sent. Your provider only ever sees encrypted text, so it doesn't matter which service you use.

Does iPGMail work with ProtonMail?

Yes, with some caveats. ProtonMail uses its own internal encryption between ProtonMail users. For standard PGP compatibility:

1. The ProtonMail user exports their public key from ProtonMail settings
2. They share that key with you
3. You import their key into iPGMail
4. You can now exchange encrypted messages using standard OpenPGP

Can I use iPGMail for business or HIPAA compliance?

Yes. iPGMail provides strong encryption suitable for:

• Business communications
• HIPAA-compliant healthcare messaging
• Legal and financial correspondence
• Journalist source protection

iPGMail supports RSA keys up to 4096-bit and modern elliptic curve cryptography, meeting or exceeding industry security standards.

Does iPGMail work on iPad?

Yes. iPGMail is a universal app that runs on both iPhone and iPad. With iCloud sync enabled, your keys are available on all your devices.

Does iPGMail work offline?

Yes. Encryption and decryption happen entirely on your device. You don't need an internet connection to decrypt messages, encrypt new ones, or manage your keys.

You only need access to send email, search keyservers, or sync with iCloud.

How does iPGMail protect my private keys?

Are decrypted files secure on my device?

Decrypted files are stored in iPGMail's sandboxed documents folder, protected by iOS security. Other apps cannot access them. For maximum security with sensitive files:

• View decrypted content within iPGMail rather than exporting it
• Keep the encrypted original as your permanent copy
• Delete decrypted copies after viewing if the content is highly sensitive

What happens if I lose my device?

Your keys remain protected by several layers: your device passcode, your app PIN if enabled, and the passphrase on each private key. If your device is lost or stolen:

• Use Find My iPhone to remotely wipe the device
• Your keys still exist wherever you originally exported them from
• Re-import your keys to a new device

How do I back up my keys?

Your private keys should exist in at least two places: your computer, where you originally created or imported them, and iPGMail on your iOS device. For additional backup:

• Export your private key to an encrypted USB drive
• Store the drive in a secure physical location
• Never store unencrypted private keys in cloud storage